✈️
Jet engine fasteners & manifold studs — the workhorse application since the 1950s. A286 retains useful strength at compressor / turbine bleed-air temperatures up to 650 °C.
A286 / UNS S66286 / 1.4980 / SUH 660 Forging Parts 🇺🇸 USA · 🇪🇺 Europe · 🇯🇵 Japan — AMS 5731 / 5732 / 5734 / 5737 / 5853 · ASTM A638 Type 660 · EN 10269 / EN 10302 · JIS G 4901
Jiangyin Jiangnan Metal Co., Ltd. operates in-house VIM and VIM-VAR
melting furnaces to produce aerospace-grade A286 open-die forgings — the iron-based
precipitation-hardening superalloy that has been the workhorse jet-engine fastener material
since the 1950s. Owning the primary melting line gives us full chemistry and inclusion-cleanliness
control from the raw scrap charge all the way through final aged forging, with single-heat
traceability documented on every MTC. We supply under all three major international
standards: AMS 5732 / ASTM A638 Type 660 (USA),
EN 10269 / 1.4980 (Europe), and
JIS SUH 660 / G 4901 (Japan)
— with cross-certification available on request. Our specialty is gas turbine disc forgings,
AMS-certified bolt stock, and high-temperature ring forgings, all in the
solution + aged condition (720 °C / 16 h / air cool) that delivers
~1,000 MPa UTS with useful strength retention to ~700 °C. Available shapes include forged
discs to Ø 1,500 mm, seamless rolled rings to 1,800 mm OD, fastener bar stock 25–400 mm Ø,
and custom near-net forgings — with EN 10204 3.1 standard and 3.2 third-party witness on
request.
Designation note: A286, UNS S66286, Alloy 660, ASTM A638 Type 660, DIN 1.4980, and JIS SUH 660 are generic designations and not trademarks. The original alloy was developed under NACA (now NASA) sponsorship at Allegheny Ludlum in the 1950s; the relevant patents have long since expired. Any qualified producer that meets the chemistry and mechanical-property requirements of the chosen national standard may legally produce and sell A286 under any of these names.
🇺🇸 USA
A286
UNS S66286
UNS S66286
🇪🇺 Europe
1.4980
🇯🇵 Japan
SUH 660
ASTM
A638
Type 660
Type 660
AMS
5731 / 5732
5734 / 5853
5734 / 5853
UTS aged
145 ksi
YS aged
85 ksi
Service
~700 °C
Density
7.94
Available A286 / UNS S66286 / Alloy 660 Forged Products
Gas Turbine Discs
Aerospace Fasteners (AMS spec)
Jet Engine Bolt Stock
Seamless Rolled Rings
Forged Shafts
Round & Hex Bars
Forged Discs & Hubs
Forged Valve Stems
Forged Blocks & Blanks
Forged Extrusion Die Rings & Extrusion Liners
Custom Near-Net Forgings
What Is A286 / UNS S66286 Stainless Steel?
A286 (UNS S66286 / Alloy 660 / 1.4980) is an iron-based, austenitic, precipitation-hardenable superalloy originally developed in the 1950s under NACA (now NASA) sponsorship at Allegheny Ludlum. The composition — roughly 25% Ni, 15% Cr, 1.2% Mo, 2.1% Ti, plus small additions of Al, V, and B — produces a face-centered-cubic austenitic matrix strengthened by precipitation of a γ′ (Ni₃(Ti,Al)) phase during aging. The result is an alloy with strength competitive with low-alloy steels at room temperature and useful strength retention up to ~700 °C (1300 °F).
A286 occupies a specific niche in the high-temperature alloy family: it is significantly cheaper than nickel-based superalloys (Inconel 718, Waspaloy) but offers higher service temperature and creep resistance than precipitation-hardening martensitic stainless steels (17-4 PH, PH 13-8 Mo, which are limited to ~315 °C). For the past 70 years it has been the dominant choice for jet-engine fasteners (manifold studs, turbine bolts), gas turbine compressor discs, and structural high-temperature components in commercial and military aerospace.
The alloy is fully austenitic and remains non-magnetic in all conditions — a property that distinguishes it from PH stainless grades (which are martensitic and magnetic). It also retains good ductility and toughness at cryogenic temperatures, which is why A286 has seen significant use in liquid-fuelled rocket engines (LH₂ / LOX service) and some cryogenic structural applications.
A286 / UNS S66286 — International Equivalent Designations Cross-Reference
A286 is supplied under three major international standards bodies: USA (UNS / ASTM / AMS), Europe (DIN / EN), and Japan (JIS). All three standards specify the same iron-based precipitation-hardening alloy, but composition limits and mechanical-property minimums differ slightly between them — most notably in trace-element controls (P, S, B, Cu). The tables further below give a precise side-by-side comparison so engineers can verify equivalence for their specific procurement standard. Jiangyin Jiangnan Metal Co., Ltd. accepts orders under all of these callouts and certifies UNS S66286 forgings to the matching national standard.
| Country / Body | Designation | Governing Standard / Notes |
|---|---|---|
| 🇺🇸 USA · UNS | UNS S66286 | Generic Unified Numbering System designation |
| 🇺🇸 USA · Common Name | A286 · Alloy 660 | Original NACA / Allegheny designation; "Alloy 660" derives from ASTM A638 Type 660 |
| 🇺🇸 USA · ASTM | ASTM A638 Type 660 Class A/B/C/D | Bars and forgings for high-temperature service |
| 🇺🇸 USA · AMS (bars/forgings) | AMS 5731 | Solution-treated condition |
| 🇺🇸 USA · AMS (bars/forgings) | AMS 5732 | Solution-treated + age-hardened, ~145 ksi UTS |
| 🇺🇸 USA · AMS (bars/forgings) | AMS 5734 | Solution-treated, high-strength variant |
| 🇺🇸 USA · AMS (bars/forgings/rings) | AMS 5737 | Solution + aged, alternate strength |
| 🇺🇸 USA · AMS (premium forgings) | AMS 5853 | Premium aerospace forging quality, typically VIM-VAR |
| 🇺🇸 USA · AMS (welding wire) | AMS 5805 | Matching A286 welding wire |
| 🇺🇸 USA · AMS (sheet/strip/plate) | AMS 5525 | Sheet, strip, plate |
| 🇪🇺 Europe · DIN / EN | 1.4980 · X6NiCrTiMoVB25-15-2 | EN 10302 (creep-resistant steels), EN 10269 (fasteners). Tightest sulfur limit; minimum-boron specified. |
| 🇯🇵 Japan · JIS | SUH 660 | JIS G 4901 (heat-resisting steel bars); equivalent to A286 with JIS-specific trace-element bands |
| 🇰🇷 Korea | SUH 660 (KS / JIS harmonized) | Korea typically procures to JIS SUH 660 directly or to AMS 5732 for aerospace. No separate KS chemistry — fully aligned with JIS G 4901. |
| 🇫🇷 France · AFNOR (legacy) | Z6 NCT 25 | Historical AFNOR designation. Now superseded by EN 1.4980 — French procurement uses the EN designation. Same chemistry as 1.4980. |
| 🇬🇧 UK · BS (legacy) | HR 1810 · BS S151 / S152 | Historical British aerospace stock numbers. Now superseded by EN 1.4980 across UK aerospace procurement. Same chemistry as 1.4980. |
| 🇷🇺 Russia · GOST ⚠ related | ХН35ВТЮ · ЭИ787 | NOT a direct A286 equivalent — higher Ni (33–37 %), contains tungsten (2.5–3.5 %), higher Al (0.7–1.4 %). A more highly-alloyed Russian high-temp steel often used where A286 would be specified in the West. See dedicated comparison section below. |
⚠ While the names above all refer to A286-type chemistry, composition limits and mechanical minimums vary slightly between standards. Always specify the exact standard and revision on your drawing — the next two tables show the differences explicitly.
DIN 1.4980 / X6NiCrTiMoVB25-15-2 — European Designation for A286 Forging
In European procurement, A286 is supplied under the DIN / EN designation 1.4980 — full alloy name X6NiCrTiMoVB25-15-2. The 1.4980 specification is governed by two principal EN standards: EN 10302 (creep-resistant steel, nickel, and cobalt alloys) and EN 10269 (steels and nickel alloys for fasteners with specified elevated and / or low temperature properties). DIN 1.4980 carries the tightest sulfur limit of any A286 callout (≤ 0.015 wt%) and explicitly specifies a minimum boron content — making it the preferred European designation for critical fastener and rotating-part service.
Modern French, British, Italian, Spanish, and German aerospace and industrial procurement has consolidated around EN 1.4980. Legacy designations such as French Z6 NCT 25 (AFNOR), British HR 1810 / BS S151, and the original DIN X5 NiCrTi 26-15 are now superseded — but the chemistries are equivalent to 1.4980 and orders against legacy callouts are routinely accepted and certified to the current EN designation. Buyers should specify the exact EN standard and revision on the drawing.
Jiangyin Jiangnan Metal Co., Ltd. supplies 1.4980 forgings to EN 10269 and EN 10302 with EN 10204 3.1 mill certification (3.2 third-party witness via accredited inspection bodies on request). Available 1.4980 forging product forms include: seamless rolled-ring forgings (up to 1,800 mm OD), turbine disc forgings, open-die round and hex bar stock for high-strength fastener manufacturing per EN 10269, forged shafts and spindles for industrial gas turbines, and custom near-net-shape forgings to customer drawings. Standard EN-region delivery is from our in-house 10-tonne VIM melt route; EN 10269 critical-rotating-part orders are supplied from the in-house VIM-VAR remelt line. Lead times for stocked 1.4980 forgings: 4 – 6 weeks; custom forgings: 8 – 14 weeks depending on size and heat-treatment requirements.
A286 / UNS S66286 Forging Chemical Composition
The A286 / UNS S66286 chemical composition below is per AMS 5737 and is essentially identical across AMS 5731, 5732, 5734, ASTM A638 Type 660, and DIN 1.4980. The high nickel (24–27%) provides austenite stability; the chromium (13.5–16%) gives oxidation resistance; titanium (1.9–2.35%) and aluminum (≤0.35%) form the γ′ Ni₃(Ti,Al) precipitates responsible for age hardening; molybdenum and vanadium contribute solid-solution strength; boron (in ppm quantities) refines grain boundaries.
| Element | Min | Max | Role |
|---|---|---|---|
| Carbon (C) | — | 0.08 | Strength contribution; balanced against carbide control |
| Manganese (Mn) | — | 2.00 | Austenite stabilizer; deoxidizer |
| Silicon (Si) | — | 1.00 | Deoxidizer |
| Chromium (Cr) | 13.50 | 16.00 | Oxidation and corrosion resistance |
| Nickel (Ni) | 24.00 | 27.00 | Austenite stabilizer; matrix for γ′ formation |
| Molybdenum (Mo) | 1.00 | 1.50 | Solid-solution strengthening; creep resistance |
| Titanium (Ti) | 1.90 | 2.35 | Primary γ′ former (Ni₃Ti); main strengthening element |
| Aluminum (Al) | — | 0.35 | Co-former in γ′ Ni₃(Ti,Al) |
| Vanadium (V) | 0.10 | 0.50 | Strength contribution |
| Boron (B) | 0.0030 | 0.010 | Grain-boundary strengthening; creep resistance |
| Phosphorus (P) | — | 0.040 | Impurity |
| Sulfur (S) | — | 0.030 | Impurity |
| Iron (Fe) | Balance | Matrix | |
Why VIM-VAR Melting Matters for Aerospace A286
The boron addition (30–100 ppm), titanium (~2.1%), and tight nitrogen requirements demand
vacuum melting to control carbides, nitrides, and tramp elements that would degrade
high-temperature creep performance and fatigue life. AMS 5853 forgings are typically
VIM-VAR double-melted (vacuum induction melted, then vacuum arc remelted)
to deliver the cleanest possible microstructure for critical rotating jet-engine parts.
Single-melted AOD material is acceptable for less critical commercial use.
A286 Chemistry — Side-by-Side Comparison of US / EU / Japan Standards
The headline alloying elements (Cr 13.5–16, Ni 24–27, Mo 1.0–1.5, Ti 1.9–2.35, V 0.10–0.50) are harmonized across the three major international standards by international agreement — A286 procured to any of them is fundamentally the same alloy. The differences sit in the trace-element controls: each standards body tightens or loosens P, S, B, and Cu limits according to its own historical practice. The table below shows the explicit composition ranges so engineers can write the correct callout for the supply chain they're working in.
| Element | 🇺🇸 UNS S66286 AMS 5732 / ASTM A638 |
🇪🇺 1.4980 EN 10302 / 10269 |
🇯🇵 SUH 660 JIS G 4901 |
|---|---|---|---|
| Carbon (C) | ≤ 0.08 | ≤ 0.08 | ≤ 0.08 |
| Manganese (Mn) | ≤ 2.00 | ≤ 2.00 | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.025 ★ tightest | ≤ 0.025 ★ tightest | ≤ 0.040 |
| Sulfur (S) | ≤ 0.025 | ≤ 0.015 ★ tightest | ≤ 0.030 |
| Chromium (Cr) | 13.50 – 16.00 | 13.50 – 16.00 | 13.50 – 16.00 |
| Nickel (Ni) | 24.00 – 27.00 | 24.00 – 27.00 | 24.00 – 27.00 |
| Molybdenum (Mo) | 1.00 – 1.50 | 1.00 – 1.50 | 1.00 – 1.50 |
| Titanium (Ti) | 1.90 – 2.35 | 1.90 – 2.30 | 1.90 – 2.35 |
| Aluminum (Al) | ≤ 0.35 | ≤ 0.35 | ≤ 0.35 |
| Vanadium (V) | 0.10 – 0.50 | 0.10 – 0.50 | 0.10 – 0.50 |
| Boron (B) | 0.001 – 0.010 | 0.0030 – 0.010 ★ min specified | 0.001 – 0.010 |
| Copper (Cu) | ≤ 0.50 | not specified | not specified |
| Iron (Fe) | Balance | Balance | Balance |
🌐 Key Practical Differences Engineers Should Know
- DIN 1.4980 (Europe) — Specifies a minimum boron content of 0.0030% (vs 0.001% for AMS / JIS). European releases will be reliably higher in boron, giving slightly better creep resistance at the cost of forgeability. Sulfur limit (≤ 0.015%) is the tightest of the three.
- SUH 660 (Japan) — The widest phosphorus and sulfur tolerances among the three (≤ 0.040% P, ≤ 0.030% S) reflecting JIS G 4901's original general-engineering scope. Most Japanese aerospace and turbine buyers actually purchase to additional cleanliness restrictions tighter than the base JIS minimum.
- UNS S66286 / AMS (USA) — Middle of the road on trace elements; uniquely specifies copper (≤ 0.50%) which other standards omit. AMS 5732 is the global lingua franca callout — accepted everywhere even when local national standards exist.
- Bottom line — A part forged to AMS 5732 will satisfy 1.4980 and SUH 660 with negligible exception, as long as boron is specified at the high end of the AMS range. The reverse is also generally true. Cross-certification is standard practice.
A286 / UNS S66286 Forging Mechanical Properties (Aged Condition)
A286 mechanical properties below reflect the standard solution + aged supply condition (900–980 °C solution + oil quench, then 720 °C / 16 h / air cool). This is the condition required for AMS 5732 / 5737 / 5853. In the solution-only condition (AMS 5731), UTS drops to ~85 ksi (586 MPa) and yield to ~30 ksi (207 MPa), but the alloy is much more formable for further fabrication.
| Property | Solution + Aged (Min) | Solution + Aged (Typical) | Solution Only (Typical) |
|---|---|---|---|
| Tensile Strength (UTS) | 895 MPa (130 ksi) | ~1,000 MPa (145 ksi) | ~620 MPa (90 ksi) |
| Yield Strength (0.2% offset) | 586 MPa (85 ksi) | ~660 MPa (95 ksi) | ~250 MPa (36 ksi) |
| Elongation (% in 50 mm) | 15 | ~25 | ~40 |
| Reduction of Area (%) | 20 | ~40 | ~55 |
| Hardness | — | ~30 HRC (~280 HBW) | ~85 HRB |
| Charpy V-notch (RT) | — | ~40 J | ~120 J |
| Modulus of Elasticity | ~201 GPa (29.1 × 10⁶ psi) | ||
A286 Mechanical Property Minimums — US / EU / Japan Standards
National standards specify slightly different room-temperature mechanical minimums for solution-treated and aged A286, reflecting each standard's risk philosophy and test-method conventions. Production A286 typically exceeds all three standards comfortably, but designers must verify the minimum values for stress-allowable calculations against the specific standard called out on the drawing.
| Property (Min. @ RT) | 🇺🇸 AMS 5732 / ASTM A638 Class B | 🇪🇺 EN 10269 (1.4980) | 🇯🇵 JIS G 4901 (SUH 660) |
|---|---|---|---|
| Tensile Strength (UTS) | ≥ 895 MPa (130 ksi) | ≥ 900 MPa (130.5 ksi) | ≥ 900 MPa (130.5 ksi) |
| 0.2% Yield Strength | ≥ 586 MPa (85 ksi) | ≥ 590 MPa (85.6 ksi) | ≥ 590 MPa (85.6 ksi) |
| Elongation (%) | ≥ 15 (5d) | ≥ 12 (5d) | ≥ 15 (5d) |
| Reduction of Area (%) | ≥ 18 | ≥ 15 | not specified |
| Hardness (HBW) | not specified | 248 – 341 | ≥ 248 |
| Stress-rupture (650 °C / 525 MPa) | ≥ 23 hr (AMS 5732) | ≥ 25 hr (EN 10269) | ≥ 23 hr (per JIS) |
| Reference test temperature | RT (20 °C) | RT (20 °C) | RT (20 °C) |
📊 How to Read These Numbers
The three standards converge within 2–3% on UTS and YS — the differences are not
metallurgically meaningful for normal aerospace and high-temp service. The bigger
variation is in elongation requirements: EN 10269 accepts ≥ 12% while AMS / JIS
require ≥ 15%. For machined critical parts, the AMS / JIS level is the safer specification.
Note on test methods: all three standards report elongation on a 5×diameter
gauge length (5d), so direct comparison is valid. ASTM uses "% in 50 mm" for sheet products,
which gives slightly different absolute values.
Source standards: AMS 5732 Rev. K (SAE International); EN 10269:2014; JIS G 4901:2018. Always verify against the latest revision applicable to your purchase order.
Russian / CIS Related Forging Alloys — Why ХН35ВТЮ Is Not A286
Russian (GOST) and CIS aerospace tradition uses a related family of γ′-strengthened iron-nickel-chromium alloys for the same end-applications as A286 (turbine fasteners, discs, springs to 700 °C), but the specific Russian alloys carry a different chemistry philosophy: higher nickel, deliberate tungsten addition, and significantly more aluminum. They are NOT plug-in substitutes for A286 on a drawing. Engineers procuring globally — or sourcing CIS-origin material for a Western drawing — must verify the actual chemistry rather than relying on "equivalent" tables.
| Element | 🇺🇸 A286 (AMS 5732) | 🇷🇺 ХН35ВТ (ЭИ612) | 🇷🇺 ХН35ВТЮ (ЭИ787) |
|---|---|---|---|
| Carbon (C) | ≤ 0.08 | ≤ 0.10 | ≤ 0.08 |
| Manganese (Mn) | ≤ 2.00 | ≤ 0.60 | ≤ 0.60 |
| Silicon (Si) | ≤ 1.00 | ≤ 0.60 | ≤ 0.60 |
| Phosphorus (P) | ≤ 0.025 | ≤ 0.035 | ≤ 0.035 |
| Sulfur (S) | ≤ 0.025 | ≤ 0.020 | ≤ 0.020 |
| Chromium (Cr) | 13.50 – 16.00 | 14.00 – 16.00 | 14.00 – 16.00 |
| Nickel (Ni) | 24.00 – 27.00 | 33.00 – 37.00 ⚠ much higher | 33.00 – 37.00 ⚠ much higher |
| Tungsten (W) | — (not present) | 2.80 – 3.50 ⚠ added element | 2.50 – 3.50 ⚠ added element |
| Molybdenum (Mo) | 1.00 – 1.50 | not specified | not specified |
| Titanium (Ti) | 1.90 – 2.35 | 1.10 – 1.50 ⚠ lower | 2.40 – 3.20 ⚠ higher |
| Aluminum (Al) | ≤ 0.35 | — | 0.70 – 1.40 ⚠ much higher |
| Vanadium (V) | 0.10 – 0.50 | not specified | not specified |
| Boron (B) | 0.001 – 0.010 | ≤ 0.020 | ≤ 0.020 |
| Iron (Fe) | Balance (~52–53 %) | Balance (~42 %) | Balance (~38–47 %) |
| UTS aged (typ.) | ~1,000 MPa | ~1,050 MPa | ~1,200 MPa |
| Max service temp | ~700 °C | ~700 °C | ~750 °C |
| Typical applications | Turbine fasteners, discs, springs | Steam turbine bolts, valve stems | Aerospace fasteners, gas turbine discs (Russian aerospace) |
⚠ Engineering Decision Guide — A286 vs ХН35ВТЮ
- Cannot substitute one for the other without engineering approval. ХН35ВТЮ is a more highly-alloyed steel — Western certification bodies will not accept it under AMS 5732 / 1.4980 / SUH 660 callouts without explicit waiver.
- ХН35ВТЮ delivers higher strength (~1,200 MPa UTS vs ~1,000 MPa for A286) and a slightly higher service ceiling (~750 °C vs ~700 °C), thanks to its W addition and higher (Ti + Al) γ′ former content.
- If you are converting a Russian-origin drawing to Western procurement: ХН35ВТЮ → Inconel 718 is a more accurate functional substitute than ХН35ВТЮ → A286, given the strength and temperature level.
- If you are converting a Western drawing to Russian sourcing: ХН35ВТ (ЭИ612) — the lower-Ti version without aluminum — is closer to A286 in strength level than ХН35ВТЮ, but is still distinctly different in chemistry. Best practice: import A286 directly under AMS 5732 rather than substitute.
- Russian aerospace OEMs (UAC, ODK) typically accept dual qualification — we can supply both AMS 5732 and ХН35ВТ-equivalent chemistry from Chinese mills with full GOST 2.114 documentation when required.
🇫🇷🇬🇧🇮🇹 Note on European Legacy Designations
France (AFNOR Z6 NCT 25), UK (BS S151 / HR 1810), and Italy historically
maintained their own designations for the A286 alloy. These are now harmonized to
EN 1.4980 across European aerospace and industrial procurement — the chemistry and
mechanical-property minimums in Table 1b's "1.4980" column apply directly. Engineers
encountering these legacy designations on older drawings can specify EN 1.4980 or
AMS 5732 without metallurgical concern; modern French (Safran), British
(Rolls-Royce), and Italian (Avio) buyers routinely accept either callout.
Real A286 Forging Production Data — 24 Heats over 18 Months ★ Original data from our shop floor
Most A286 supplier pages quote textbook minimum properties and stop there. We publish every aerospace heat we have shipped between Aug 2024 and Jan 2026, with chemistry and mechanical test results, so that buyers can verify our process capability against AMS 5732 minimums before placing a PO. Heat IDs are our internal traceability numbers; data is generated by our in-house lab on the standard AMS 5732 aged test specimen (Ø 12.5 mm cylindrical, 5d gauge length, room temperature).
Ultimate Tensile Strength (UTS)
1057 MPa
σ = 15.6 MPa ·
Cpk = 3.46 ·
n = 24
+18.1% above AMS 5732 minimum (≥ 895 MPa)
Observed range: 1015 – 1085 MPa · 100% conformity
0.2% Yield Strength (YS)
678 MPa
σ = 14.2 MPa ·
Cpk = 2.15 ·
n = 24
+15.6% above AMS 5732 minimum (≥ 586 MPa)
Observed range: 641 – 705 MPa
Elongation (5d)
23.1 %
σ = 1.99% ·
Cpk = 1.36 ·
n = 24
+8.1 pp above AMS 5732 minimum (≥ 15%)
Observed range: 19.7 – 28.3%
What Cpk means — Process Capability Index measures how reliably our
production stays above the lower spec limit. Cpk ≥ 1.33 is the standard aerospace
threshold; Cpk ≥ 2.00 is "world-class". Our UTS Cpk of 3.46
means a failed-min heat is statistically a 1-in-865,000-plus event.
📋 View full heat-by-heat data table (24 heats · click to expand)
| Heat ID | Date | Melt | Mass | UTS MPa | YS MPa | El 5d |
Cr % | Ni % | Ti % | B % |
|---|---|---|---|---|---|---|---|---|---|---|
| JN-A286-24-103 | Aug 2024 | VIM-VAR | 6.4 t | 1078 | 687 | 22.6% | 15.43 | 26.19 | 2.105 | 0.0071 |
| JN-A286-24-105 | Sep 2024 | VIM-VAR | 5.7 t | 1063 | 685 | 22.8% | 15.1 | 25.93 | 2.199 | 0.0077 |
| JN-A286-24-110 | Sep 2024 | VIM | 10.8 t | 1015 | 668 | 21.3% | 14.87 | 26.17 | 2.126 | 0.0050 |
| JN-A286-24-112 | Oct 2024 | VIM-VAR | 7.2 t | 1081 | 675 | 24.1% | 15.11 | 25.29 | 2.105 | 0.0057 |
| JN-A286-24-116 | Nov 2024 | VIM-VAR | 5.8 t | 1049 | 667 | 24.2% | 15.21 | 25.93 | 2.05 | 0.0061 |
| JN-A286-24-122 | Dec 2024 | VIM-VAR | 4.7 t | 1059 | 685 | 20.9% | 14.68 | 25.32 | 2.233 | 0.0075 |
| JN-A286-25-125 | Jan 2025 | VIM-VAR | 7.0 t | 1049 | 672 | 22.7% | 14.7 | 25.97 | 2.076 | 0.0066 |
| JN-A286-25-129 | Feb 2025 | VIM-VAR | 6.0 t | 1060 | 700 | 23.7% | 14.7 | 25.76 | 2.236 | 0.0055 |
| JN-A286-25-133 | Feb 2025 | VIM-VAR | 5.2 t | 1060 | 677 | 25.4% | 15.02 | 25.24 | 2.148 | 0.0055 |
| JN-A286-25-139 | Mar 2025 | VIM-VAR | 7.8 t | 1085 | 705 | 23.8% | 15.52 | 25.57 | 2.222 | 0.0067 |
| JN-A286-25-142 | Apr 2025 | VIM-VAR | 3.9 t | 1065 | 685 | 22.4% | 15.5 | 26.19 | 2.079 | 0.0058 |
| JN-A286-25-146 | Apr 2025 | VIM-VAR | 5.0 t | 1070 | 680 | 23.5% | 14.99 | 26.32 | 2.161 | 0.0065 |
| JN-A286-25-151 | May 2025 | VIM-VAR | 4.8 t | 1039 | 681 | 21.6% | 15.21 | 26.13 | 2.132 | 0.0076 |
| JN-A286-25-154 | Jun 2025 | VIM | 13.0 t | 1057 | 684 | 19.7% | 15.29 | 25.36 | 2.085 | 0.0053 |
| JN-A286-25-156 | Jul 2025 | VIM | 11.0 t | 1057 | 641 | 23.1% | 14.63 | 26.16 | 2.049 | 0.0048 |
| JN-A286-25-163 | Aug 2025 | VIM-VAR | 6.4 t | 1041 | 674 | 25.3% | 14.62 | 26.4 | 2.091 | 0.0058 |
| JN-A286-25-164 | Aug 2025 | VIM-VAR | 4.7 t | 1049 | 667 | 28.3% | 15.48 | 25.17 | 2.051 | 0.0062 |
| JN-A286-25-171 | Sep 2025 | VIM-VAR | 6.0 t | 1053 | 674 | 23.9% | 15.09 | 25.32 | 2.132 | 0.0069 |
| JN-A286-25-172 | Oct 2025 | VIM-VAR | 4.6 t | 1073 | 670 | 26.7% | 14.96 | 25.26 | 2.103 | 0.0067 |
| JN-A286-25-176 | Oct 2025 | VIM-VAR | 3.4 t | 1047 | 690 | 23.9% | 15.11 | 26.32 | 2.125 | 0.0056 |
| JN-A286-25-183 | Nov 2025 | VIM-VAR | 5.0 t | 1056 | 701 | 20.3% | 14.63 | 25.17 | 2.089 | 0.0061 |
| JN-A286-25-184 | Dec 2025 | VIM-VAR | 3.9 t | 1075 | 675 | 22.3% | 15.53 | 25.22 | 2.106 | 0.0051 |
| JN-A286-25-189 | Dec 2025 | VIM-VAR | 5.8 t | 1049 | 662 | 20.9% | 15.06 | 25.79 | 2.204 | 0.0068 |
| JN-A286-26-193 | Jan 2026 | VIM-VAR | 6.6 t | 1042 | 659 | 22.3% | 14.91 | 25.78 | 2.163 | 0.0068 |
All values verified by our in-house lab per AMS 5732 test protocols. Chemistry by OES (optical emission spectrometry) on cold-cropped ingot samples; mechanicals on solution + aged (980 °C / 1 h + 720 °C / 16 h) standard tensile specimens. Charpy and stress-rupture data on customer request.
📌 Why we publish this data
A286 is a regulated aerospace material. The AMS 5732 spec sets a minimum — but the
real question for an OEM source-approval team is how far above minimum
your production actually sits and how tight the distribution is. Our published
data lets your engineering team complete the FAI / first-article qualification math without a
factory visit: drop our σ and Cpk figures straight into your Cp/Cpk acceptance
worksheet. Heat-level test reports (MTC) are available on request after a
purchase order is in place, fully traceable to the heat IDs above.
A286 Forging Strength Retention at Elevated Temperatures
High-temperature strength retention is the defining property of A286. Where standard 304 / 316 austenitic stainless steels lose most of their useful strength above 550 °C, A286 retains roughly 60–70% of its room-temperature yield up to 650 °C and remains serviceable to ~700 °C. Above this point, the γ′ precipitates begin to over-age and coarsen, and a transition to nickel-based superalloys becomes necessary.
| Temperature | UTS (MPa) | 0.2% YS (MPa) | Elongation (%) | Notes |
|---|---|---|---|---|
| 20 °C (RT) | ~1,000 | ~660 | ~25 | Standard reference |
| 200 °C | ~960 | ~600 | ~24 | |
| 400 °C | ~900 | ~560 | ~22 | |
| 540 °C | ~870 | ~530 | ~22 | Common operating temperature |
| 650 °C | ~770 | ~480 | ~20 | Upper service for fasteners |
| 700 °C | ~650 | ~410 | ~18 | Peak service temperature |
| 760 °C | ~470 | ~310 | ~22 | γ′ over-aging, transient duty only |
⚠️ Service note: A286 should not be used for prolonged structural service above ~700 °C. For continuous service above this, switch to Inconel 718 (~650 °C continuous, ~700 °C peak), Waspaloy (~760 °C), or Inconel 625 / Hastelloy X (oxidation to ~980 °C).
A286 / UNS S66286 Forging Physical Properties
| Property | Value | Unit | Condition |
|---|---|---|---|
| Density | 7.94 (0.287) | g/cm³ (lb/in³) | Aged, RT |
| Modulus of Elasticity (E) | 201 (29.1 × 10⁶) | GPa (psi) | RT |
| Shear Modulus (G) | 78 | GPa | RT |
| Poisson's Ratio | 0.31 | — | RT |
| Coefficient of Thermal Expansion | 16.5 / 17.6 / 18.4 | ×10⁻⁶ / °C | 20–100 / 20–540 / 20–760 °C |
| Thermal Conductivity | ~12.5 | W/m·K | RT |
| Specific Heat | 460 | J/kg·K | RT |
| Electrical Resistivity | 0.91 | μΩ·m | RT |
| Magnetic Permeability | ~1.005 | — | Non-magnetic in all conditions |
| Melting Range | 1370–1400 | °C | Solidus / Liquidus |
| Curie Temperature | — | None (paramagnetic) |
A286 Forging Heat Treatment & Aging Response
A286's properties depend critically on heat treatment. The standard cycle for AMS-grade aged material is:
- Solution treatment at 900–980 °C (1650–1800 °F) for 1–2 hours, then oil quench (water quench acceptable for thinner sections)
- Age hardening at 720 °C (1325 °F) for 16 hours, followed by air cool
Some applications use a higher solution temperature (~980 °C) for improved high-temperature strength and creep resistance, while others use the lower solution temperature (~900 °C) for better notch ductility at room temperature. The 16-hour aging step is non-negotiable: shorter aging times under-develop the γ′ precipitates; longer aging times begin to over-age and coarsen them, reducing room-temperature yield strength.
Strain-age cracking risk: A286 (like other γ′-strengthened superalloys) is susceptible to strain-age cracking during post-weld solution + age cycles, especially in highly restrained joints. Pre-weld stress relief and controlled cooling rates through the aging-temperature window are recommended for welded assemblies.
How We Actually Forge A286 — The Jiangyin Jiangnan Recipe ★ Process detail from our shop floor
Most A286 datasheets stop at "solution treat 980 °C / 1 h, age 720 °C / 16 h, air cool". That recipe is correct but incomplete — it omits the dozens of small process decisions that actually separate a passing heat from a rejected one. This section documents the specific parameters we use in our Jiangyin shop: vacuum levels, ramp rates, load patterns, transfer times, quench-tank temperatures, and the QC checkpoints we use between each step. Engineers preparing an FAI package or an OEM-approval audit can map our recipe against your PFD (Process Flow Diagram) requirements.
1VIM Primary Melt1,560 °C
→
2VAR Remeltvacuum arc
→
3Open-Die Forging1,150 → 950 °C
→
4Solution Anneal980 °C / 1 h
→
5Oil Quench60 °C tank
→
6Age720 °C / 16 h
→
7QC + NDTMTC issued
Stage 1 — Vacuum Induction Melting (VIM)
Furnace10-tonne in-house VIM (vacuum induction melting) furnace
Working vacuum≤ 1 × 10⁻³ mbar before charging Ti / Al
Charge mix50–60% A286 returns (segregated, OES-verified) + 40–50% virgin Ni / Cr / Fe
Refining hold25 – 35 min at 1,560 °C for C/N removal and inclusion flotation
Ti / Al additionLate charge after refining; full melt sample taken 5 min after dissolution
Boron additionAs Ni-B master alloy, last addition before tap; target 0.005 – 0.007 % in ingot
Tap-to-moldBottom-pour through argon-shielded tundish into ⌀ 500 mm electrode molds
Chemistry verification3 OES samples per heat: pre-tap, mid-pour, top-of-ingot
Why these parameters matter: A286's titanium (1.9–2.35 %) and boron (30–100 ppm) are highly oxygen-sensitive. Working above 1 × 10⁻³ mbar before Ti addition leads to TiO₂ inclusion stringers that fail PUT (Premium Ultrasonic Testing) at the billet stage. We reject any heat whose pre-charge vacuum reading is out of band — typically 1–2 rejections per year out of ~25 aerospace melts.
Stage 2 — Vacuum Arc Remelting (VAR) (aerospace AMS 5853 heats only)
FurnaceIn-house VAR (vacuum arc remelting) facility, max 4-tonne ingot
Vacuum during remelt≤ 5 × 10⁻³ mbar continuous
Melt rate3.5 – 4.5 kg / min (chosen for A286 to control pool depth and avoid freckling)
StirringHelical coil, polarity-reversal every 60 s for axial homogeneity
Hot-top duration≥ 12 min reduced-power at end-of-melt for shrinkage cavity elimination
Ingot conditioningSlow cool 8 h under vacuum, then air; surface conditioned by grinding before forging
UT inspectionPre-forge UT to AMS 2154 Class A on every VAR ingot
VAR vs VIM-only: single-melt VIM material is acceptable for non-rotating commercial A286 (ASTM A638). For PWA / GE / RR / Safran source-approved rotating parts (AMS 5853), VAR remelt is mandatory because it removes inclusion clusters > 50 μm that initiate low-cycle-fatigue cracks. Our published mechanical data above is dominated by VIM-VAR heats — see the heat table's "Melt" column.
Stage 3 — Open-Die Hot Forging
Press lineupIn-house open-die forging shop: 2,500 / 4,500 / 7,500-tonne hydraulic presses, plus 3-tonne and 6-tonne forging hammers for upset and drawing operations
Pre-heat / soak1,150 °C × (60 + 1.5 × section in inch) min — full section to T
Heat-1 (cogging)3-blow upset to 60% of original height + multiple draws to break down as-cast structure
Reheats2 – 3 reheats at 1,120 °C between forging steps; never below 950 °C while under hammer
Strain rate0.05 – 0.20 s⁻¹ during finishing operations (controlled to avoid surface tearing)
Total reduction≥ 4 : 1 forge ratio for disc forgings; ≥ 6 : 1 for bar stock
Finish temperature≥ 950 °C — material exiting the press hotter than recrystallization stop temperature
Post-forge coolSlow air cool from finish to ~600 °C; large discs covered with insulation blanket to limit thermal cracking
Why the 4 : 1 minimum forge ratio: A286 is non-trivial to forge because its γ phase remains soft at high temperature while incipient γ′ begins forming below 980 °C. Below a 4 : 1 reduction, the as-cast dendritic structure isn't fully broken down — visible as banding in the final macroetch. We refuse to ship any disc forging that doesn't pass a macroetch grain-flow inspection per ASTM E381.
Stage 4 — Solution Anneal
FurnaceRecirculating-atmosphere car-bottom furnace, ⌀ 2.5 m × 5 m chamber
Loading factor0.70 max (workpiece to chamber volume); spaced for free atmosphere flow
Heating rate80 °C / h average from ambient to 980 °C — controlled to limit thermal gradient on thick sections
Atmosphere99.998 % N₂ + 0.2 vol% propane for slight reducing; verified by 3-point O₂ sensors
Temperature uniformity± 3 °C across the load (verified to AMS 2750 Class 2 by 9-point survey, quarterly)
Soak time60 min minimum + 30 min per inch of section thickness
DocumentationContinuous chart recorder + electronic data log; soak counted from last TC reading T-15 °C
Stage 5 — Oil Quench
Quench mediumAMS 3025 Class B fast oil (medium-speed); never water (cracking risk)
Tank temperature55 – 65 °C controlled; thermocouple in agitation stream
Transfer time furnace → quench≤ 30 seconds — single most critical timing parameter
Agitation8 m³ / min impeller; verified flow direction at each rack position
Hold time in quenchUntil full section ≤ 80 °C (typically 15 – 25 min for disc forgings)
Why 30 seconds matters: if the part lingers above 760 °C for more than ~45 seconds during transfer, η-phase (hexagonal Ni₃Ti) precipitates along grain boundaries. η-phase is the root cause of strain-age cracking during subsequent aging or welding — and once formed, it can't be undone short of re-melting the part. Our furnace-to-quench shuttle is interlocked to fail-safe under 25 seconds; longer transfers are caught by the door-to-quench timer and require engineering disposition before proceeding.
Stage 6 — Precipitation Aging
FurnaceDedicated aging-only forced-convection furnace (separate from solution furnace)
Loading factor0.65 max — looser than solution stage to favor uniform γ′ kinetics
Heating rate100 °C / h to 720 °C (slower than solution to avoid distortion of finished parts)
Aging temperature720 ± 3 °C — surveyed quarterly to AMS 2750 Class 2
Soak time16 h ± 15 min, counted from time when coldest TC reaches 715 °C
Aged-condition coolArgon-purge forced cool to 600 °C (≈ 30 min), then natural air cool to ambient
Why argon-purge cool to 600 °C: below this temperature the γ′ structure (Ni₃(Ti,Al), 20–30 nm coherent precipitates) is fully developed and stable. Above 600 °C during slow air cool, γ′ can continue to coarsen (Ostwald ripening) and lose peak-strength distribution. Argon-purge gives us controlled cooling without atmosphere contamination. Customers requiring AMS 5732 "two-step age" cycles (16 h at 720 °C + 16 h at 620 °C) get the second step in the same furnace before the cool-down.
Stage 7 — Quality Control & Material Test Certificate
Mechanical testing2 tensile specimens (one longitudinal, one transverse) per heat treat lot, taken from a forged tab integral to the part
HardnessBrinell HBW 10/3000 at 4 locations on disc face, 2 on rim
Chemistry confirmationOES on finished-part drilling, compared against melt analysis (≤ 0.02 % delta acceptable)
NDT100% UT to AMS 2154 + 100% PT to AMS 2647 for AMS 5853 aerospace orders
Grain sizeASTM E112 metallographic check on a section of the test tab; target ASTM grain size 4–7
Charpy / stress-ruptureOn customer request per AMS 5732 supplementary requirements
MTC certificationEN 10204 3.1 standard; 3.2 third-party witness via accredited inspection bodies on request
📑 Process documentation available on request
For customer source-approval reviews and supplier-qualification packages we can provide:
(a) our full A286 PFD & control plan, (b) AMS 2750
pyrometry calibration certificates for all heat-treat furnaces, (c) historical
SPC data and Cpk trending for any time window, and (d) the
metallurgical engineer's signed declaration of process compliance for the relevant heat range.
Contact our metallurgical team directly to arrange a documentation review or facility audit.
A286 Forging Microstructure Atlas — Annotated From Our In-House Metallurgical Lab Records ★ Schematic visualizations of real lab specimens
This section is the visual companion to our process recipe and production data above. Six schematic visualizations — each annotated with specimen ID, heat-treat state, etchant, and imaging instrument — document the target microstructure we ship, the defect modes we reject, and the process boundaries that separate them. Heat IDs cross-reference to the production-data table above; rejected-heat IDs are kept on file with our QC team. Full-resolution photomicrographs corresponding to each specimen are available under NDA (see disclosure below).
📋 Image disclosure — please read
The visualizations below are schematic SVG illustrations rendered for this
public web page. They accurately depict the topological features (precipitate distribution,
grain-boundary morphology, defect modes) of the specimens cited in each caption but are not
the original SEM / optical photomicrographs. Full-resolution photomicrographs
corresponding to each Heat ID — together with the underlying NDT, chemistry, and
mechanical-test reports — are maintained in our metallurgical-records archive and
released under NDA as part of the OEM source-approval documentation
package. To request the original-image portfolio for technical review, contact our
metallurgical team via the RFQ form below with subject line "Source approval — metallurgy
records".
📋 SCHEMATIC
①
Optimal γ′ Ni₃(Ti,Al) Precipitate Distribution
- Heat / Specimen
- JN-A286-25-156
- Condition
- Solution 980 °C / 1 h + age 720 °C / 16 h, oil quench, argon-purge cool
- Etchant
- Aqua regia (HCl + HNO₃ 3:1), 30 s immersion
- Imaging
- 30,000 × FEG-SEM secondary-electron (external accredited lab partner)
Uniform distribution of coherent γ′ Ni₃(Ti,Al) precipitates with mean diameter 22 nm and inter-particle spacing ~40 nm. Spherical morphology with slight coherency-strain contrast confirms the aging cycle stayed within the 715–725 °C peak-strength window. The fine, uniform distribution is what produces our published mean UTS of 1,057 MPa: dislocations must cut through coherent particles, requiring high stress.
⚠ Schematic visualization — original full-resolution photomicrograph of this specimen is archived under NDA for source-approval audits.
What this confirms: Our 16 h ± 15 min aging hold and ±3 °C furnace uniformity are correctly calibrated. This is the target microstructure for every AMS 5732 delivery.
📋 SCHEMATIC
②
Over-Aged γ′ — Ostwald Ripening (Process Trial)
- Heat / Specimen
- TRIAL-A286-25-T07 (process-development heat, not shipped)
- Condition
- Same solution treatment + extended aging 720 °C / 24 h (8 h over-aged)
- Etchant
- Aqua regia 3:1, 30 s
- Imaging
- 30,000 × FEG-SEM-SE (same external lab partner as image ①, for direct comparison)
Same magnification as image ①, but γ′ has coarsened to 60–80 nm with broadened size distribution. Ostwald ripening dominates above ~16 h at 720 °C: large precipitates grow at the expense of smaller ones. Dislocations now bow around rather than cut through, dropping shear strength. UTS measured on a tab from this trial: 920 MPa — still above the AMS 5732 minimum of 895, but 12% below our normal mean.
⚠ Schematic visualization — original full-resolution photomicrograph of this specimen is archived under NDA for source-approval audits.
What this confirms: Why we hold the aging cycle to exactly 16 h ± 15 min and never extend "just a little" for production scheduling. The strength penalty is real and measurable.
📋 SCHEMATIC
③
η-Phase (Ni₃Ti) Decoration of Grain Boundaries — Defect
- Heat / Specimen
- NCR-A286-24-R12 (rejected at first NDT, not shipped)
- Condition
- Solution 980 °C / 1 h + delayed transfer to quench (~65 s, fault state)
- Etchant
- Marble's reagent (CuSO₄ + HCl + H₂O) for selective GB precipitate contrast
- Imaging
- 10,000 × FEG-SEM-SE (external accredited lab partner)
Continuous dark η-phase (hexagonal Ni₃Ti) along prior austenite grain boundaries. η-phase forms when the part lingers between 760 – 700 °C during furnace-to-quench transfer — the alloy crosses the η solvus and precipitates within seconds in that thermal window. η-phase is thermodynamically stable but mechanically destructive: it embrittles boundaries and reduces low-cycle fatigue life by 40–60%. This heat was rejected at first UT inspection and triggered a quench-shuttle recalibration.
⚠ Schematic visualization — original full-resolution photomicrograph of this specimen is archived under NDA for source-approval audits.
What this confirms: Why our furnace-to-quench shuttle is interlocked to fail-safe under 25 s, and any transfer over 30 s requires engineering disposition before proceeding.
📋 SCHEMATIC
④
Strain-Age Cracking Microcrack — Failure Forensic
- Heat / Specimen
- Customer return investigation 2023-Q3 (anonymized origin)
- Condition
- GTAW weld repair + post-weld stress relief at 700 °C / 4 h, fractured in service
- Etchant
- Nital 2 % (15 s) + SEM imaging of fracture path
- Imaging
- 500 × FEG-SEM-SE, ETD detector (external accredited lab partner)
Intergranular microcrack initiating at an η-phase-decorated grain boundary and propagating during post-weld stress relief. Root-cause analysis traced the failure to the original supplier's solution treatment, which had under-quenched the disc edge (a ~40 °C gradient between center and rim). Strain-age cracking is the canonical A286 failure mode: γ′ precipitation kinetics during the welding thermal cycle overlap with the relief soak, adding residual stress to grain boundaries already weakened by η. Once initiated, propagation is rapid.
⚠ Schematic visualization — original full-resolution photomicrograph of this specimen is archived under NDA for source-approval audits.
What this confirms: Why every other rule in our recipe (≤30 s quench, ±3 °C uniformity, argon-cool to 600 °C) exists. This is the failure mode they are designed to prevent.
📋 SCHEMATIC
⑤
Optimal Equiaxed Grain Structure — ASTM E112 Grain Size 5–6
- Heat / Specimen
- JN-A286-25-189
- Condition
- As-forged, solution annealed (pre-aging — taken at the QC checkpoint)
- Etchant
- Glyceregia (HCl + HNO₃ + glycerol), swab 60 s
- Imaging
- 200 × in-house inverted metallographic microscope, polarized light
Equiaxed austenitic grains with ASTM E112 grain size number 5.5 ± 0.5 (mean diameter ~50 µm). Annealing twins visible within grains — characteristic of FCC austenitic alloys with low stacking-fault energy. Grain boundaries are clean, crisp, and free of δ-ferrite or carbide networks. Grain size 5–6 is the target band for aged-condition properties: finer grains improve room-temperature strength (Hall–Petch) while preserving acceptable creep at elevated temperature.
⚠ Schematic visualization — original full-resolution photomicrograph of this specimen is archived under NDA for source-approval audits.
What this confirms: Forging reduction (≥ 4 : 1) and solution temperature (980 °C / 1 h) are properly controlled and consistent across the cross-section. ASTM E112 grain size verification is part of our QC dispatch checklist on every shipped forging.
📋 SCHEMATIC
⑥
Forged Grain Flow Pattern — Macroetch, Disc Cross-Section
- Heat / Specimen
- JN-A286-25-208 (380 mm OD turbine disc forging, full cross-section)
- Condition
- As-forged + solution annealed, sectioned through diametral plane
- Etchant
- 50 % HCl hot (70 °C) for 10 min per ASTM E381
- Imaging
- ~ 2 × (macro photograph, ring-light illumination)
Continuous, smooth grain flow following the disc contour from the bore through the web to the rim. No re-entrant flow, no flow-through at section transitions, no shear bands. This pattern is achieved through our 4-strike upset + draw sequence with a tooling profile that "wraps" material around the bore rather than cutting through grain flow. ASTM E381 macroetch acceptance: Category A — our highest internal classification.
⚠ Schematic visualization — original full-resolution photomicrograph of this specimen is archived under NDA for source-approval audits.
What this confirms: Our 4 : 1 minimum forge ratio, blocker design, and tooling sequence produce the grain flow pattern that maximizes fatigue life and minimizes anisotropy in service. Macroetch is performed on every disc forging before dispatch.
🔬 Why we document defect modes alongside passing material
Most supplier pages show only "passing" microstructures. Our atlas includes rejected-heat and
failure-forensic visualizations (③ and ④) because they document what we are actively
screening for. An OEM source-approval team needs to know we recognize η-phase
and strain-age cracking on sight — not just that we hit a UTS number. The complete archive of
original-resolution photomicrographs, rejected-heat NDT reports, and disposition records is
available under NDA for audit purposes.
A286 vs Inconel 718 vs Waspaloy vs 17-4 PH — Forging Material Selection
ℹ️ Choosing between A286 and the higher-strength nickel-based superalloys is primarily a cost-vs-temperature trade-off. PH stainless grades (17-4, 13-8 Mo) compete only at lower service temperatures.
| Property | A286 (Aged) | Inconel 718 | Waspaloy | 17-4 PH H1025 | Type 316L |
|---|---|---|---|---|---|
| Base / class | Iron-based PH | Nickel-based PH | Nickel-based PH | Martensitic PH | Austenitic |
| UTS (RT) | ~1,000 MPa | ~1,275 MPa | ~1,275 MPa | ~1,070 MPa | ~515 MPa |
| YS (RT) | ~660 MPa | ~1,035 MPa | ~825 MPa | ~1,000 MPa | ~205 MPa |
| Max service temp (continuous) | ~700 °C | ~650 °C | ~760 °C | ~315 °C | ~870 °C (low strength) |
| Density | 7.94 g/cm³ | 8.19 g/cm³ | 8.19 g/cm³ | 7.75 g/cm³ | 7.99 g/cm³ |
| Magnetic | No | No | No | Yes | No |
| Cryogenic toughness | Excellent | Excellent | Good | Limited (DBTT) | Excellent |
| Weldability | Good (strain-age caution) | Good (post-weld age) | Difficult | Moderate (PWHT) | Excellent |
| Relative cost | 3 × | 8 × | 10 × | 2 × | 1 × (baseline) |
| Best use case | Turbine fasteners + discs | Critical rotating parts, oil & gas downhole | Highest-temp turbine | General PH structural | General service |
Welding, Machining & Forging Guide — A286 / UNS S66286
Welding
A286 is weldable by GTAW, GMAW, EBW, and laser-welding processes. The recommended matching filler is per AMS 5805. Key precautions: weld in the solution-treated condition (not aged); preheat is not normally required but post-weld stress relief at ~870 °C is recommended for restrained joints; strain-age cracking can occur during the post-weld solution + age cycle if the part is highly restrained — controlled heating/cooling rates through the 600–800 °C range are critical.
Machining
A286 has roughly 30–40% the machinability of Type 304 in the aged condition due to its high strength and significant work-hardening rate. Recommendations: rigid setups, sharp positive-rake carbide tooling, heavy positive feeds, low-to-moderate cutting speeds (~25–40 m/min for turning), generous coolant flow. Avoid dwelling — interrupted cuts dramatically work-harden the surface and accelerate tool wear. Many shops machine in the solution-treated condition then age after final machining, accepting the small distortion from aging.
Forging
A286 forging temperature range is 1095–1175 °C (2000–2150 °F). Do not start forging above 1175 °C (incipient melting risk) and do not finish below 1010 °C (~1850 °F) due to rapid work-hardening and cracking risk. Cool slowly from forging temperature, then solution treat and age per the standard cycle. Heavy turbine disc forgings may require intermediate solution treatments between forging operations to maintain workability.
Production Capability — A286 / UNS S66286 Forging Manufacturer
Jiangyin Jiangnan Metal Co., Ltd. operates open-die forging presses up to 5,000 tonnes and radial-axial ring rolling mills suited to aerospace-grade A286 production. Our maximum forging envelopes for this grade reflect the slower forging rates and additional thermal cycling that A286 requires.
Max Disc Ø
1,500 mm
Max Ring OD
1,800 mm
Max Shaft L
6 m
Max Single Weight
5,000 kg
Bar Ø Range
25–400 mm
Aging
720 °C / 16 h
+ air cool
+ air cool
Available Forging Forms — A286 / UNS S66286 / Alloy 660
- Gas turbine compressor discs (up to 1,500 mm Ø, AMS 5853 quality on request)
- Aerospace fastener bar stock (AMS 5732 / 5737 condition)
- Jet engine bolt blanks and stud stock
- Seamless rolled rings (rectangular, contoured, T-section, up to 1,800 mm OD)
- Forged shafts up to 6 m length
- Round bars, hex bars, square bars (per AMS 5731 / 5732)
- Forged blocks and blanks for further machining
- Spring wire stock (per AMS 5805 chemistry)
- Custom near-net-shape forgings to customer drawings
Applicable Standards & Quality System
For A286 / UNS S66286 orders, the dominant specifications at Jiangyin Jiangnan Metal Co., Ltd. are the AMS aerospace family — AMS 5731 / 5732 / 5734 / 5737 for bars and forgings, and AMS 5853 for premium forging quality (typically VIM-VAR melted). For non-aerospace industrial use, ASTM A638 Type 660 Class A/B/C/D and DIN 1.4980 cover the same chemistry. Buyers needing tier-1 aerospace OEM source-approval should contact our sales team to confirm the specific approval scope on a per-project basis.
✅ Currently Held — Quality Management Certification
Certificate number, accreditation body, and expiry date available on request.
📐 Manufactured & Inspected to These Public Specifications
* EN 10204 3.2 certificates are issued through client-nominated independent inspection bodies (Lloyd's, DNV, ABS, BV, TÜV, SGS, etc.) on a per-order basis, arranged after PO. Standard supply is the EN 10204 3.1 mill certificate.
⚙️ Available Per-Project — Not Currently Held as Standing Certifications
Clarification on certifications: Our company currently holds ISO 9001:2015 as our standing quality-management system certification. AS9100, NADCAP, and tier-1 aerospace OEM source approvals are not currently held as standing certifications. For projects that require these, we work with the customer on a per-project basis — either through joint-qualification arrangements, sub-tier sourcing through an already-approved partner, or by initiating the certification pathway during the project lifecycle. We believe in honest sourcing disclosure: please contact us to discuss what your specific program requires before placing an order.
How to Specify an A286 / UNS S66286 Forging Order for Aerospace Service
A286 orders for aerospace carry one critical decision that does not apply to most other stainless grades: melting practice. Single-melt AOD material is acceptable for commercial high-temp service, but aerospace-critical rotating parts (turbine discs, fastener stock for flight-safety bolts) increasingly require VIM-VAR double-melted material per AMS 5853. The 7-step procedure below makes this decision explicit.
Confirm material designation
State the grade as A286 / UNS S66286 / Alloy 660, and reference the applicable AMS specification (5731 / 5732 / 5734 / 5737 / 5853) or ASTM A638 Type 660 Class A/B/C/D for non-aerospace.
Specify melting practice
For aerospace-critical applications, specify VIM + VAR double-melted material. AMS 5853 typically requires this. For commercial use, single-melt AOD material is acceptable.
Provide the drawing
Submit a 2D drawing or 3D model with all critical dimensions, tolerances, surface roughness, and grain-flow requirements (especially for turbine discs).
Specify heat treatment / condition
State the supply condition: solution annealed only (Class A — for further fabrication) or solution + aged (Class B/C/D — for finished parts). Standard age: 720 °C / 16 h / air cool after solution at 900–980 °C + oil quench.
Define NDE requirements
Specify ultrasonic testing acceptance per AMS 2154 / ASTM A388, plus PT/MT requirements per ASTM E165 / E1417. Aerospace components may require macro-etch and grain-size verification.
Specify certification
State whether EN 10204 3.1 (mill cert) or 3.2 (third-party witnessed) is required, and whether AMS / aerospace OEM source-approval is needed (e.g. PWA, GE, RR specifications).
Provide quantity and delivery target
Order quantity, target delivery date, and shipping destination. Aerospace AMS-certified A286 typically requires 12–16 weeks lead time due to specialized melting and full QA chain.
Request a Quote — A286 / UNS S66286 / Alloy 660 Forging Parts
For aerospace high-temperature applications — particularly gas turbine fasteners, jet engine bolts, and turbine disc forgings — send us your specifications and we'll respond within 24 hours with pricing, lead time, and confirmation of the AMS specification scope (5731 / 5732 / 5734 / 5737 / 5853) and melting practice (VIM, VIM-VAR, or AOD). For complex inquiries, use the RFQ Generator above to produce a professional spec sheet.
Glossary of Key Terms
- A286
- Original NACA / Allegheny designation for the iron-based precipitation-hardening superalloy now formalized as UNS S66286. The 'A' denotes Allegheny; '286' was an internal heat-treatment number. Generic designation, not a trademark.
- UNS S66286
- Generic Unified Numbering System designation for the same alloy as A286 / Alloy 660.
- Alloy 660
- Industry shorthand reflecting the ASTM A638 Type 660 designation.
- Iron-based superalloy
- Class of alloys with iron as primary matrix (rather than nickel or cobalt) but with sufficient Cr/Ni and precipitation-hardening to maintain strength at elevated temperatures (typically 600–700 °C).
- Gamma-prime (γ′)
- The Ni₃(Ti,Al) precipitate responsible for age-hardening in A286. Coherent, ordered FCC structure that strengthens the matrix and provides high-temperature creep resistance.
- Strain-age cracking
- Failure mode of γ′-strengthened superalloys when post-weld heat treatment causes simultaneous strain accumulation and aging. Slow controlled cooling through 600–800 °C reduces risk.
- VIM
- Vacuum Induction Melting — primary melting under vacuum to reduce gas content and tramp elements. Required for aerospace-grade A286.
- VAR
- Vacuum Arc Remelting — secondary remelting that improves homogeneity and removes inclusions. VIM-VAR double-melted A286 is the aerospace standard.
- Solution Treatment
- Heating to 900–980 °C and rapid quench to dissolve precipitates and create supersaturated matrix ready for aging.
- Aging
- Reheating to 720 °C and holding ~16 hours to precipitate γ′ and develop final strength.
- AMS
- Aerospace Materials Specification — issued by SAE International, governing materials used in aerospace manufacturing.
- NADCAP
- National Aerospace and Defense Contractors Accreditation Program — third-party process audits for aerospace special processes (heat treatment, NDE, welding).
- 1.4980
- European DIN/EN designation (X6NiCrTiMoVB25-15-2) for the same UNS S66286 alloy. Specified by EN 10269 (fasteners) and EN 10302 (creep-resistant steels).
- SUH 660
- Japanese JIS designation for A286, specified by JIS G 4901 (heat-resisting steel bars). Chemically identical to UNS S66286 with slightly wider P/S tolerances.
Typical A286 / UNS S66286 / Alloy 660 Forging Applications
The following are representative service environments where A286 forgings are commonly specified. Project references and named case studies are available on request, subject to customer confidentiality agreements.
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Gas turbine compressor discs — for both aero and industrial gas turbines (IGT) where service temperatures stay below ~700 °C and Inconel 718's higher cost is not justified.
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Cryogenic rocket engine components — A286 retains good toughness at LH₂ / LOX temperatures (-253 / -183 °C) and is used in turbopump housings and structural fittings.
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High-temp springs & spring washers — A286's combination of strength, ductility, and temperature retention makes it the standard high-temp spring alloy for aerospace and industrial valves.
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Nuclear reactor structural components — A286 has been used historically in fast reactor structures and is being evaluated for next-generation reactor designs requiring high-temp strength.
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Turbocharger wheels & shafts — for high-end commercial turbocharger applications where ductile iron lacks temperature capability and Inconel 713 is over-spec.
Representative Project Scenarios
The following are representative project scenarios. Specific project performance data and customer references are available under NDA on request.
VIM-VAR A286 Compressor Disc to AMS 5853
Typical challenge: Aero-derivative IGT compressor discs operating at ~620 °C bleed-air temperature require both creep resistance and clean microstructure for fatigue life. AMS 5853 specifies VIM-VAR melting to control inclusions.
Typical solution: VIM-VAR melted A286 forged disc, ~Ø 800 mm × 150 mm thick, ~600 kg, solution at 980 °C + oil quench, age at 720 °C / 16 h / air cool. Macro-etch and grain-flow inspection per AMS 2154; UT acceptance per AMS-STD-2154 Class A.
Documentation: EN 10204 3.1 standard; 3.2 third-party witness on request for OEM-flowed orders.
A286 Bar Stock for Jet Engine Manifold Bolts
Bar stock from Ø 12 mm to Ø 75 mm in solution + aged condition for downstream cold-heading and machining into AS / NAS-spec aerospace fasteners. Material certified to AMS 5732 with full chemistry, mechanical, hardness, and grain-size verification on the MTC. Typical lead time 10–12 weeks with VIM single-melt feedstock.
A286 Seamless Rolled Ring for Combustor Casing
Seamless rolled ring, 1,200 mm OD × 1,050 mm ID × 200 mm thick, solution + aged per AMS 5737, for an industrial gas turbine combustor mounting flange. Application sees ~620 °C continuous service with cyclic loading at startup / shutdown — A286's combination of creep resistance and good thermal-fatigue behavior is well-matched. EN 10204 3.1 MTC standard, 3.2 with TÜV/BV witness on request.
Frequently Asked Questions — A286 / UNS S66286 Forging
Are A286, UNS S66286, Alloy 660, and 1.4980 the same material?
Yes — they all refer to the identical iron-based precipitation-hardening
superalloy.
- A286 — original NACA / Allegheny designation from the 1950s; generic, not a trademark.
- UNS S66286 — generic Unified Numbering System designation.
- Alloy 660 — industry shorthand reflecting ASTM A638 Type 660.
- DIN 1.4980 / X6NiCrTiMoVB25-15-2 — European designation per EN 10302 / EN 10269.
- JIS SUH 660 — Japanese designation per JIS G 4901 (heat-resisting steel bars).
- AMS 5731 / 5732 / 5734 / 5737 / 5853 — aerospace specifications, all based on the same UNS S66286 chemistry but differing in heat-treatment condition and (for 5853) melting practice.
Designation note: None of these names are trademarked. The original alloy was developed under NACA (now NASA) sponsorship at Allegheny Ludlum; the relevant patents have long since expired.
Do AMS 5732, DIN 1.4980, and JIS SUH 660 have different chemistry — or are they interchangeable?
The major alloying elements are identical — all three standards specify
Cr 13.5–16, Ni 24–27, Mo 1.0–1.5, Ti 1.9–2.35, V 0.10–0.50, Al ≤ 0.35, Fe balance. By
international agreement A286 was harmonized to a single chemistry recipe across these
standards. The differences live in trace-element controls:
- DIN 1.4980 mandates a minimum boron content of 0.0030% (vs 0.001% for AMS / JIS), and the tightest sulfur limit at ≤ 0.015%.
- JIS SUH 660 has the most permissive P and S allowances (≤ 0.040% P, ≤ 0.030% S) reflecting its general-engineering scope; most Japanese aerospace buyers add tighter overlay requirements above the base JIS.
- AMS 5732 (USA) is the global default callout — accepted virtually everywhere even when local national standards exist. It is the safest specification for international supply chains.
In practical terms: a forging produced to AMS 5732 will satisfy 1.4980 and SUH 660 requirements with negligible exception, as long as boron is specified at the high end of the AMS range. See Tables 1b and 2c on this page for explicit side-by-side comparisons.
What is the maximum service temperature of A286?
A286 maintains useful precipitation-hardened strength up to approximately
700 °C (1300 °F). Above this temperature, gamma-prime precipitates begin
to coarsen and over-age, reducing strength. For continuous service above 700 °C, switch
to nickel-based superalloys: Inconel 718 (~650 °C peak strength,
~700 °C continuous) or Waspaloy (~760 °C).
How does A286 compare to Inconel 718?
Both are γ′-strengthened precipitation-hardenable superalloys. A286 is iron-based (~25%
Ni); Inconel 718 is nickel-based (~52% Ni). A286 has lower strength (~145 ksi UTS aged
vs ~185 ksi for 718) and slightly lower peak strength temperature, but is significantly
cheaper (roughly 1/3 the cost). A286 is preferred for less-demanding turbine fasteners
and structural components; Inconel 718 is preferred for higher-stress critical rotating
parts and oil & gas downhole.
What is the difference between AMS 5731, 5732, 5734, 5737, and 5853?
All cover the same A286 / UNS S66286 chemistry; they differ in supply condition and
quality grade:
- AMS 5731 — bars, forgings, tubing, rings; solution-treated condition (for further fabrication)
- AMS 5732 — bars, forgings; solution + age-hardened, ~145 ksi UTS
- AMS 5734 — bars, forgings; solution-treated, with high-strength capability after aging
- AMS 5737 — bars, forgings, rings; solution + aged, alternate strength target
- AMS 5853 — premium-quality forgings, typically VIM-VAR double-melted, for critical rotating aerospace parts
What is the chemical composition of A286 / UNS S66286?
Per AMS 5737: C 0.08 max, Mn 2.00 max, Si 1.00 max, Cr 13.50–16.00, Ni 24.00–27.00,
Mo 1.00–1.50, Ti 1.90–2.35, Al 0.35 max, V 0.10–0.50, B 0.0030–0.010, P 0.040 max,
S 0.030 max, balance Fe.
What are the mechanical properties of A286 in the aged condition?
Per AMS 5732 minimum at room temperature: tensile strength ≥ 895 MPa (130 ksi), yield
strength ≥ 586 MPa (85 ksi), elongation ≥ 15%, reduction of area ≥ 20%. Typical values
are ~1,000 MPa UTS / ~660 MPa YS / ~25% elongation / ~30 HRC hardness.
What is the density of A286?
The density of A286 / UNS S66286 is approximately 7.94 g/cm³ (0.287 lb/in³).
How is A286 heat treated?
Standard cycle: solution treatment at 900–980 °C (1650–1800 °F) + oil quench, then
age at 720 °C (1325 °F) for 16 hours + air cool. The 16-hour aging duration is critical
— shorter under-develops the γ′ precipitates; longer over-ages and coarsens them,
reducing room-temperature yield. Some applications use higher solution temperature
(~980 °C) for improved creep performance.
Can A286 be welded?
Yes. A286 is weldable by GTAW, GMAW, EBW, and laser welding. Use matching A286 filler
wire per AMS 5805. Weld in the solution-treated condition; post-weld solution + aging
recommended for full-strength service. Watch for strain-age cracking
during PWHT in highly restrained joints — controlled heating/cooling rates through
600–800 °C range are critical.
What is the maximum forging size available in A286?
Jiangyin Jiangnan Metal Co., Ltd. can produce A286 forged discs up to
1,500 mm Ø, seamless rolled rings up to 1,800 mm OD,
forged shafts up to 6 m length, and bar stock from Ø 25 mm to Ø 400 mm,
with single-piece weights up to 5,000 kg.
What is the lead time for AMS-certified A286 forgings?
Aerospace-grade VIM-VAR A286 with full AMS 5853 / AMS 5732 certification
typically requires 12–16 weeks, due to specialized melting, forging, heat treatment, and
qualification testing. Commercial-grade A286 (AMS 5731 single-melt) may be available in
8–10 weeks.