1.3980 / X5NiCrTiMoV26-15 Non-Magnetizable Forgings German Werkstoff 1.3980 · UNS S66286 chemistry · equivalent to A286, Alloy 660, 1.4980, JIS SUH 660 and GH2132 · rings, discs, shafts, bars and flanges from our own VIM and VIM-VAR melt

Published: 12 May 2022 · Last updated: 22 September 2026 · Technically reviewed by the Metallurgical Engineering Team, Jiangyin Jiangnan Metal Co., Ltd. · All values verified against DIN EN 10269, SAE AMS and mill datasheets listed under Sources.

• 1.3980 X5NiCrTiMoV26-15
• UNS S66286 A286
• 1.4980 EN 10269
• SUH 660
• GH2132
• µ_r 1.007–1.010
• R_m 900–1150 MPa
• Service ≤704 °C
• Density 7.94 g/cm³

What Is 1.3980 / X5NiCrTiMoV26-15?

Two properties, taken together, are what put 1.3980 on a drawing:

1. It is genuinely non-magnetic, and stays that way. Ordinary austenitic stainless steels such as 304 and 316 are non-magnetic when annealed but pick up ferromagnetic deformation martensite as soon as they are cold worked or machined hard. With ≈26 % nickel, the austenite in 1.3980 is thermodynamically stable: no martensite forms, and relative permeability stays at µ_r ≈ 1.007–1.010 in every supply condition and down to −196 °C.
2. It is strong while being non-magnetic. Most genuinely amagnetic materials are either weak (annealed austenitics, copper alloys) or expensive (nickel-base superalloys). Age-hardened 1.3980 reaches ≥600 MPa proof strength at room temperature and still holds ≥430 MPa at 600 °C, at roughly a third of the raw-material cost of Inconel 718.

The alloy was developed in the 1950s under NACA (now NASA) sponsorship at Allegheny Ludlum and has been the dominant jet-engine fastener alloy ever since. 1.3980, A286, UNS S66286, Alloy 660 and 1.4980 are generic designations, not trademarks; the original patents expired long ago, and any qualified producer meeting the chemistry and mechanical-property requirements of the chosen national standard may produce and sell to these names.

1.3980 vs 1.4980 vs A286: Why One Alloy Has Two German Numbers

Sources: German mill datasheets for 1.3980 (HSM, Quick Metall, Remy Stahl); DIN EN 10269 and EN 10302 for 1.4980; SAE AMS 5737 and ASTM A638 for UNS S66286. Verify against the revision named on your purchase order.

1.3980 Equivalent Designations: Germany, Europe, USA, Japan, China, UK, France

Cross-references compiled from the issuing bodies' own scope clauses and from German, Japanese and Chinese mill designation tables. Composition limits vary slightly between standards, so always name the exact standard and revision on the drawing.

1.3980 Chemical Composition (wt %)

Composition per German mill datasheets for Werkstoff 1.3980. The same band, with the trace-element variations shown in Table 4, governs 1.4980, AMS 5731/5732/5734/5737, ASTM A638 Grade 660 and JIS SUH 660.

Trace-element differences across the four national standards

1.3980 Mechanical Properties: Aged and Solution-Annealed

EN column per DIN EN 10269 for 1.4980, condition +AT+P, diameter ≤ 160 mm. Typical columns are representative production values for this chemistry and are not specification minima. Property minima change between standard revisions, so verify against the revision named on your purchase order.

Proof strength at elevated temperature

Minimums under the other major standards

1.3980 Magnetic and Physical Properties

Permeability, density, modulus, resistivity and melting range from mill datasheets for the UNS S66286 chemistry (ATI, Special Metals, Carpenter). Elevated-temperature modulus and expansion per DIN EN 10269 for 1.4980. Values are typical and are not specification minima or maxima.

1.3980 Heat Treatment: Two Solution Routes and the 16-Hour Age

1.3980 Forging, Welding and Machining

Forging

• Start temperature 1038–1121 °C (1900–2050 °F), short soaking period. Do not exceed 1121 °C, or incipient melting becomes a risk.
• Finish temperature ≥ 927 °C (1700 °F). Below this the alloy work-hardens rapidly and surface tearing and cracking follow.
• Two to three reheats at ≈1100 °C between forging steps on heavy sections; never continue under the hammer below 950 °C.
• Strain rate 0.05–0.20 s⁻¹ during finishing operations to avoid surface tearing.
• Minimum 4 : 1 forge ratio for disc forgings, 6 : 1 for bar stock, so the as-cast dendritic structure is fully broken down. Below that, banding shows up in the macroetch.
• Slow air cool from finish temperature to ≈600 °C; large discs covered with insulation blanket to limit thermal cracking. Then solution treat and age.
• Heavy disc forgings may need intermediate solution treatments between forging operations to restore workability.

Welding

Weld in the solution-treated condition, never aged; keep restraint low and heat input moderate; then solution treat and age for full-strength service. A widespread claim needs qualifying: 1.3980 is not in the classic strain-age-cracking group. Its Al + Ti content is about 2.3–2.7 wt %, comfortably below the ≈4 wt % threshold on the Prager–Shira weldability diagram that separates readily weldable alloys from the genuinely SAC-prone ones (René 41, Waspaloy, Udimet 500, IN738). What the alloy does suffer is heat-affected-zone liquation cracking, and highly restrained weldments can still crack during the 720 °C ageing treatment. Control heating and cooling rates through the 600–800 °C range. We supply 1.3980 forgings in the solution-treated condition precisely so that customers can weld before final ageing, and will supply matching AMS 5805 filler from the same heat on request.

Machining

Roughly 30–40 % of Type 304 machinability in the aged condition, because of the high strength and a significant work-hardening rate. Use rigid setups, sharp positive-rake carbide tooling, heavy positive feeds, low-to-moderate cutting speeds (≈25–40 m/min for turning) and generous coolant flow. Avoid dwelling; interrupted cuts work-harden the surface dramatically and accelerate tool wear. Many shops machine in the solution-treated condition and age afterwards, accepting the small distortion from ageing. It is still appreciably easier to machine than nickel-base grades such as Inconel 718.

Cold working

In the solution-treated condition 1.3980 cold draws and forms satisfactorily. It is stiffer than Types 316 and 310 and work-hardens rapidly. Cold work plus ageing is how the high-strength fastener specs are reached. AMS 5853 at ≈15 % cold reduction gives 1103 MPa (160 ksi) capability and AMS 5726 at 40–50 % reduction reaches 1379 MPa (200 ksi). Importantly, cold work does not make the alloy magnetic: the austenite is stable, so no deformation martensite forms.

1.3980 Forged Products We Manufacture

• Seamless rolled ringsRectangular, contoured and T-section, OD to 1,800 mm. Radial-axial ring rolling.
• Forged ringsUpset-and-pierce rings and retaining rings where rolling is not economic.
• Forged discs & disksCompressor and turbine discs, hubs and blanks to Ø1,500 mm, grain-flow inspected.
• Forged shafts & spindlesPlain, stepped and eccentric shafts to 6 m length.
• Forged barsRound Ø25–400 mm, plus flat, square and hex sections for fastener and spring stock.
• Forged flangesWeld-neck, blind, slip-on and special profiles to drawing.
• Forged bushings & sleevesNon-magnetic bearing and guide components.
• Forged tube sheetsHeat-exchanger tube sheets and thick-section plate blanks.
• Forged valve partsStems, bodies, bonnets and seat rings for high-temperature service.
• Forged gears & slewing ringsGear blanks and non-magnetic transmission components.
• Forged cylinders & pipesHollow forgings, liners and tubes machined from solid.
• Forged nozzles & near-net partsCustom open-die forgings to your drawing.

Every forging is ultrasonically tested to EN 10228-3, SEP 1921 or ASTM A388 as specified on the order, with AMS 2154 Class A available for aerospace-grade work.

Typical 1.3980 Applications

• Non-magnetic instrumentationSensor and magnetometer housings, survey-tool bodies, MRI and particle-accelerator fixtures, anywhere µ_r must stay below ≈1.01 after machining.
• Naval & submarine hardwareGerman stockholder catalogues list 1.3980 under the special designation U-Boot-Stahl, reflecting its use in non-magnetic naval components.
• Cryogenic non-magnetic equipmentDuctile and non-magnetic to −196 °C and below. Superconducting-magnet supports, LH₂ / LOX hardware, turbopump housings and structural fittings.
• Gas-turbine fasteners & studsThe dominant jet-engine fastener alloy since the 1950s. Holds useful strength at compressor and turbine bleed-air temperatures to 650 °C.
• Compressor & turbine discsAero and industrial gas turbines below ≈700 °C, where Inconel 718's cost is not justified.
• High-temperature springsThe standard hot spring alloy for aerospace and industrial valves, combining strength, ductility and temperature retention.
• Valve stems & steam-turbine partsThe traditional JIS SUH 660 market: stems, spindles and seat rings for steam and industrial turbine valves.
• Downhole & subsea hardwareNon-magnetic fasteners and components for offshore oil and gas, where corrosion resistance plus permeability control both matter.
• Power plant & power generationThe sector German suppliers list against 1.3980: power-plant construction, mechanical engineering and power generation components.

Common 1.3980 Specification Errors, Corrected

A set of errors about this material number has travelled through supplier catalogues and distributor datasheets until it reads as settled fact. Several of them will put the wrong alloy in a purchase order. We checked each designation against the issuing body's own title and scope, and publish what we found.

1. "1.3980 is used for nitric acid coolers, NPK fertiliser plants, seawater desalination and polythionic acid service."

   Those are 904L, 6Mo and duplex applications, not 1.3980. With only 13.5–16 % Cr, 1.0–1.5 % Mo and no copper, 1.3980 has aqueous corrosion resistance comparable to ordinary austenitic stainless steel. That is good enough for moderate service, but it is not a wet-corrosion alloy and should not be specified against strongly oxidising acids, chloride stress-corrosion or seawater duty. This misattribution appears widely because catalogue text is copied between grade pages. For those services, see 904L or a super-duplex grade instead. Basis: composition of 1.3980 against alloy-selection practice for oxidising-acid and chloride service.

2. "1.3980 has R_p0.2 of 200–600 MPa and elongation of 14–16 %."

   Those numbers mix two different supply conditions into one table and are not usable as a specification. The 200 MPa figure belongs to the solution-annealed condition and the 600 MPa figure is the aged minimum. Elongation is not specified as a range with a maximum at all. DIN EN 10269 requires A ≥ 15 % for the aged condition and typical production runs 23–25 %. The correct aged figures are R_m 900–1150 MPa, R_p0.2 ≥ 600 MPa, A ≥ 15 %, KV ≥ 50 J. Basis: DIN EN 10269, condition +AT+P, d ≤ 160 mm. See Table 5.

3. "1.3980 and 1.4980 are different alloys."

   They are the same alloy family in two different Werkstoff groups. 1.39xx indexes non-magnetizable steels; 1.49xx indexes high-temperature steels. The chemistries are identical except in trace-element bands (see Table 1), and both point back to UNS S66286. Treating them as different alloys leads buyers to reject perfectly conforming material, or to pay for a second qualification that is not needed. What is different is the implied reason for selection, and therefore which properties should be written into the acceptance criteria. Basis: German material-number group structure; composition tables for 1.3980 and EN 1.4980.

4. "1.3980 corresponds to AISI 403 / UNS S40300."

   Wrong alloy entirely. AISI 403 / UNS S40300 is a martensitic 12 % chromium turbine-blade steel, and martensitic means ferromagnetic, the exact opposite of what someone specifying 1.3980 needs. This cross-reference appears in at least one widely mirrored online material finder and has propagated from there. The correct UNS number for 1.3980 is S66286. Basis: UNS S40300 is a 11.5–13.0 % Cr martensitic grade with no nickel, titanium or boron addition.

5. "1.3980 is limited to 700 °C and Inconel 718 to 650 °C, so 1.3980 runs hotter."

   Both alloys top out near 700 °C. The precise load-bearing limit for 1.3980 is 704 °C (1300 °F). Inconel 718 is not chosen for a higher ceiling. It is chosen for far higher retained strength at that same ceiling, roughly 860–950 MPa yield at 650 °C against 1.3980's ≈480 MPa. Separately, the oxidation limit of 816 °C continuous is routinely confused with the strength limit; the two differ by more than 100 °C. Basis: mill datasheets for UNS S66286 and AMS 5663 for Inconel 718. Compare on our Inconel 718 page.

6. "1.3980 is highly susceptible to strain-age cracking during post-weld heat treatment."

   Overstated. Al + Ti is about 2.3–2.7 wt %, well below the ≈4 wt % threshold on the Prager–Shira weldability diagram that separates readily weldable alloys from the genuinely SAC-prone ones, and this chemistry does not appear on published SAC-susceptible alloy lists. What it does suffer is heat-affected-zone liquation cracking, and highly restrained weldments can crack during the 720 °C age. Weld solution-treated, keep restraint and heat input low, then solution treat and age. Basis: Prager–Shira weldability criterion; Carpenter CarTech A-286 weldability note.

Production Capability: 1.3980 Forging Manufacturer in Jiangyin, China

• Max disc Ø 1,500 mm
• Max ring OD 1,800 mm
• Max shaft length 6 m
• Max single weight 5,000 kg
• Bar Ø 25–400 mm
• Presses 2,500 / 4,500 / 7,500 t
• Hammers 3 t / 6 t
• Founded 2008

Melt routes offered for 1.3980

Titanium at 1.9–2.3 % and boron at 30–100 ppm are highly oxygen-sensitive, which is why vacuum melting matters for this chemistry: working above 1 × 10⁻³ mbar before the titanium addition produces TiO₂ inclusion stringers that fail premium ultrasonic testing at the billet stage. No AMS product number mandates VIM-VAR by itself, so the melt route must be written on the purchase order.

Certification and quality system

We hold ISO 9001:2015 as our standing quality-management system certification; the certificate number, accreditation body and expiry date are available on request. Forgings are manufactured and inspected to EN 10269, EN 10302, AMS 5731 / 5732 / 5734 / 5737, ASTM A638 Grade 660, ASTM A453 Grade 660 and JIS G 4311 as called out on the order, with UT to EN 10228-3 / SEP 1921 / ASTM A388 or AMS 2154, PT to ASTM E165 / AMS 2647, grain size to ASTM E112 and macroetch to ASTM E381. EN 10204 3.1 mill certification is standard; 3.2 certificates are issued through client-nominated independent inspection bodies (Lloyd's, DNV, ABS, BV, TÜV, SGS) on a per-order basis.

Honest disclosure on certifications: AS9100, NADCAP and tier-1 aerospace OEM source approvals are not currently held as standing certifications. For projects requiring them we work with the customer on a per-project basis: joint qualification, sub-tier sourcing through an already-approved partner, or initiating the certification pathway during the project. Please discuss what your programme requires before placing an order.

How to Specify a 1.3980 Forging Order

1. Confirm the material designation. State the grade as 1.3980 / X5NiCrTiMoV26-15 (UNS S66286) and reference the applicable standard: EN 10269 or EN 10302 for European supply, AMS 5731 / 5732 / 5734 / 5737 for aerospace, ASTM A638 Grade 660 Type 1 / Type 2 or ASTM A453 Grade 660 Class A–D for industrial, JIS G 4311 SUH 660 for the Japanese market.
2. State the magnetic requirement, if any. For example "µ_r ≤ 1.01 measured per ASTM A342 on the finished part after machining". If permeability is why 1.3980 was chosen, it belongs on the order as an acceptance criterion, not as an assumption.
3. Specify melting practice. VIM + VAR double melt for critical rotating, cryogenic or aerospace parts; VIM for standard supply; EAF + VOD + ESR for commercial volume. No AMS product number mandates double melting on its own, so write it explicitly, for example "VIM + VAR, AMS 2154 Class A".
4. Provide the drawing. A 2D drawing or 3D model with critical dimensions, tolerances, surface roughness and any grain-flow requirement, which matters especially for discs and rolled rings.
5. Specify the heat-treatment condition. Solution annealed only (for further forming, machining or welding) or solution + aged (finished parts), and which solution temperature: 982 °C for creep life, 899 °C for short-time tensile. Standard age: 720 °C / 16 h / air cool.
6. Define NDE requirements. Ultrasonic acceptance per EN 10228-3, SEP 1921, ASTM A388 or AMS 2154; PT or MT per ASTM E165 / E1417 / AMS 2647; macroetch and grain-size verification where required.
7. State certification and quantity. EN 10204 3.1 mill certificate or 3.2 third-party witnessed; order quantity, target delivery date and shipping destination. Indicative lead times: stocked sizes 4–6 weeks; custom forgings 8–14 weeks; full aerospace AMS chain with VIM-VAR melt 12–16 weeks.

Frequently Asked Questions About 1.3980

Cite This Page

If you are quoting figures from this page in a specification, report or material-selection study, this is the citation:

Manufacturer of record for the forgings described on this page: Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China 214423 · sales@steelforgepieces.com · +86-189-2135-9659.

Source Standards and References

• DIN EN 10269: Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties (mechanical minima, elevated-temperature proof strength, modulus and thermal expansion for 1.4980).
• DIN EN 10302: Creep-resisting steels, nickel and cobalt alloys.
• SAE AMS 5731 / 5732 / 5734 / 5737: UNS S66286 bars, forgings and rings; solution and precipitation heat-treatment conditions and property minima.
• SAE AMS 5853 / 5726 / 5895 / 5805 / 5525: cold work-strengthened bar and wire, welding grade, matching filler and flat-rolled product.
• ASTM A638/A638M: Precipitation hardening iron base superalloy bars, forgings and forging stock for high-temperature service (Grade 660, Types 1 and 2).
• ASTM A453/A453M: High-temperature bolting with expansion coefficients comparable to austenitic stainless steels (Grade 660, Classes A–D).
• JIS G 4311: Heat-resisting steel bars and wire rods (SUH 660).
• GB/T: GH2132 (0Cr15Ni25Ti2MoAlVB) Chinese superalloy designation.
• ASTM A342/A342M: Standard test methods for permeability of weakly magnetic materials.
• EN 10204: Types of inspection documents (3.1 and 3.2).
• EN 10228-3 · SEP 1921 · ASTM A388 · AMS 2154: ultrasonic examination of forgings.
• Mill datasheets for the UNS S66286 chemistry: ATI A286™, Special Metals INCOLOY® alloy A-286, Carpenter CarTech® A-286 (physical properties, permeability, forging and machining practice).
• German mill and stockholder datasheets for Werkstoff 1.3980 / X5NiCrTiMoV26-15 (composition band, non-magnetizable group classification, delivery forms).

Property minima change between standard revisions. Always verify values against the standard and revision named on your purchase order, and treat the values on this page as engineering reference data rather than as a contractual specification. Binding values are those stated on the EN 10204 certificate issued with your material.

Related grades on this site

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• Inconel 718
• Waspaloy
• Incoloy 901
• Nimonic 80A
• 17-4PH
• PH13-8Mo
• Nitronic 50
• 904L