# 1.2779 Forgings - Rolled Rings, Extrusion Tooling & Bars **Source:** https://www.steelforgepieces.com/Nickel-Alloy/1.2779.html **Publisher:** Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China **Published:** 2019-05-14; **Last reviewed:** 2026-08-04 Werkstoff 1.2779; X6NiCrTiMoVB25-15-2; equivalent to A-286 / UNS S66286 / EN 1.4980 / Alloy 660 / GH2132 --- ## Short answer 1.2779 is the German Werkstoff number for **X6NiCrTiMoVB25-15-2**, a precipitation-hardening austenitic iron-nickel-chromium superalloy of roughly 25 % Ni, 15 % Cr, 2 % Ti and 1.25 % Mo, balance iron. It is the same alloy as **A-286 / UNS S66286 / 1.4980**; the 1.2779 number is used when it is bought as a hot-working tool material for extrusion tooling. After solution treatment and ageing it reaches at least 895 MPa tensile strength, stays non-magnetic, and holds useful strength up to about **700 degC (1300 degF)**. **Jiangyin Jiangnan Metal Co., Ltd.**, an open-die forging factory in Zhouzhuang Town, Jiangyin, Jiangsu, China, forges 1.2779 into seamless rolled rings up to dia. 3,500 mm, extrusion mandrels, dies, liners, liner holders, pressure pads, dummy blocks, die holders and inserts, stems, sleeves, shafts, discs, flanges, forged pipes and round bars - **one piece minimum, made to drawing**, ESR melted, solution treated and aged, UT tested, EN 10204 3.1 or 3.2 certificate, 25-45 days. --- ## 1. At a glance | Item | Value | |---|---| | Werkstoff number | 1.2779 (tool-material listing); 1.4980 (EN 10269, EN 10302); 1.4944 (bolting) | | DIN / EN name | X6NiCrTiMoVB25-15-2 (older: X5NiCrTi26-15) | | UNS / trade names | S66286; A-286; Alloy 660; Incoloy A-286; Pyromet A-286; Tinidur | | Alloy family | Precipitation-hardening austenitic Fe-Ni-Cr superalloy, gamma-prime Ni3(Ti,Al) hardened | | Melting route | EAF + AOD/VOD + ESR standard; VIM + VAR on request | | Delivery condition | Forged -> solution treated + aged -> rough machined (finish machined on request) | | Tensile / proof | Rm >= 895 MPa; Rp0.2 >= 585 MPa; 248-341 HBW | | Service temperature | -196 degC to approx. 700 degC continuous; scaling resistance to approx. 800 degC | | Magnetic | No - non-magnetic in all conditions, mu-r approx. 1.001 | | Forging window | Soak 1120-1150 degC; finish > 950-980 degC; ratio >= 4:1 | | NDT | UT to EN 10228-3 / ASTM A388 / SEP 1921; PT on request (MT not applicable) | | Certificate | EN 10204 3.1 standard; 3.2 with SGS, BV, TUV, LR or DNV | | Max ring size | OD 3,500 mm; single piece to 25,000 kg | | MOQ / lead time | 1 piece, made to drawing / 25-45 days after drawing approval | | Made by | Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin, Jiangsu, China | --- ## 2. 1.2779 vs 1.4980 vs 1.4944 - which number goes on the order? All three Werkstoff numbers describe the same iron-nickel-chromium alloy. - **1.2779** - hot-work tool material listing. Used when the alloy is bought for extrusion mandrels, dies, liners, dummy blocks and stems. Fine as a drawing callout. - **1.4980** - the number in EN 10269, EN 10302 and VdTUV 435/3, for fasteners and creep-resisting parts. This is what most European mill certificates actually carry, and it is the safest number to order to. - **1.4944** - the same alloy in an older bolting listing at a different strength condition. - **A-286 / UNS S66286** - ASTM A453, ASTM A638, AMS 5731/5737. The name most of the world uses. There is no EN product standard that says "1.2779"; there are EN 10269 and EN 10302, and both say 1.4980. This is why some European mills print the cross-reference as *approximately* 1.2779. If a drawing says 1.2779 and the certificate says 1.4980, the material is correct. **Recommended purchase-order wording:** `1.2779 / 1.4980 / A-286, UNS S66286, to ASTM A453 Gr 660 Class A` --- ## 3. Equivalent grades worldwide | System | Designation | |---|---| | Germany (Werkstoff) | 1.2779; 1.4980; 1.4944; X6NiCrTiMoVB25-15-2; X5NiCrTi26-15; Tinidur | | USA (UNS / trade) | UNS S66286; A-286; A286; Alloy 660; Incoloy A-286; Pyromet A-286 | | ASTM | A453 Gr 660 (Class A/B/C/D); A638 Gr 660; B637 | | AMS (aerospace) | AMS 5525; 5731; 5732; 5734; 5737; 5804 (weld wire); 5853; 5895 | | EN | EN 10269; EN 10302; VdTUV 435/3 - grade 1.4980 | | Japan | JIS SUH 660; SUS 660 | | China (GB/T) | GH2132 (formerly GH132); 0Cr15Ni25Ti2MoAlVB | | France (AFNOR) | Z6NCTDV25-15B; Z6NCT25; Z5NCTDV26-15B; EZ6NCT25 | | UK (BS) | HR 51-55; HR 650 | --- ## 4. Chemical composition (% by weight) Two specification windows compared, because they are not identical. | Element | ASTM A453 Gr 660 | EN 10269 (1.4980) | Typical, our heats | |---|---|---|---| | C | <= 0.08 | 0.03-0.08 | 0.045 | | Si | <= 1.00 | <= 1.00 | 0.45 | | Mn | <= 2.00 | <= 2.00 | 1.10 | | P | <= 0.025 | <= 0.025 | 0.012 | | S | <= 0.025 | **<= 0.015** | 0.004 | | Cr | 13.50-16.00 | 13.50-16.00 | 14.8 | | Ni | 24.00-27.00 | 24.00-27.00 | 25.4 | | Mo | 1.00-1.50 | 1.00-1.50 | 1.25 | | Ti | 1.90-2.35 | **1.90-2.30** | 2.10 | | V | 0.10-0.50 | 0.10-0.50 | 0.28 | | Al | <= 0.35 | <= 0.35 | 0.18 | | B | 0.0010-0.010 | **0.003-0.010** | 0.005 | | Fe | Balance, approx. 53 % | Balance | Balance | **Correction to a figure that circulates widely:** the aluminium limit is **0.35 % max, not 0.035 %**. A number of supplier pages carry the wrong decimal. A purchase order restricting Al to 0.035 % will reject correct material. --- ## 5. Mechanical properties at 20 degC, solution treated + aged | Property | Specified minimum | Typical achieved | |---|---|---| | Tensile strength Rm | 895 MPa (130 ksi) | 1,000-1,100 MPa | | 0.2 % proof strength Rp0.2 | 585 MPa (85 ksi)* | 690-760 MPa | | Elongation A (4D) | 15 % | 18-25 % | | Reduction of area Z | 18 % | 25-40 % | | Hardness | 248-341 HBW | 280-320 HBW (28-34 HRC) | | Impact KV, 20 degC | on request | 45-75 J | | Impact KV, -196 degC | on request | 35-55 J (no DBTT) | | Stress rupture (A453 Cl. A) | 650 degC / 379 MPa, >= 100 h | passed, >= 5 % elongation | | Fatigue limit (rotating bend, 10^7) | - | approx. 380-430 MPa | \* ASTM A453 Grade 660 **Class D** requires 725 MPa (105 ksi) minimum proof strength. Specify the class on the order - it sets the ageing cycle and cannot be corrected afterwards. --- ## 6. Strength at temperature (typical, guidance) | Temperature | Rm | Rp0.2 | Elongation | |---|---|---|---| | -196 degC | approx. 1,300 MPa | approx. 900 MPa | 20 % | | 20 degC | 1,000-1,100 MPa | 690-760 MPa | 18-25 % | | 200 degC | approx. 960 MPa | approx. 650 MPa | 20 % | | 400 degC | approx. 930 MPa | approx. 620 MPa | 20 % | | 540 degC | approx. 900 MPa | approx. 600 MPa | 19 % | | 650 degC | approx. 760 MPa | approx. 590 MPa | 18 % | | 700 degC | approx. 640 MPa | approx. 530 MPa | 20 % | | 760 degC | approx. 420 MPa | approx. 360 MPa | 25 % | 1.2779 keeps roughly 85 % of its room-temperature proof strength at 650 degC and about 75 % at 700 degC. It is not the strongest alloy at room temperature - H13 and 17-4PH both start higher - but it has the flattest curve above 550 degC and crosses above H13 at roughly 600 degC. --- ## 7. Physical properties | Property | Value | |---|---| | Density | 7.94 g/cm3 (0.287 lb/in3) | | Melting range | 1,370-1,400 degC | | Modulus of elasticity, 20 degC | approx. 200 GPa | | Modulus of elasticity, 650 degC | approx. 154 GPa | | Thermal expansion | approx. 16.4 um/m.K (20-100 degC); 17.6 (20-500 degC); 18.4 (20-700 degC) | | Thermal conductivity, 20 degC | approx. 12.6 W/m.K | | Thermal conductivity, 650 degC | approx. 22.5 W/m.K | | Specific heat | approx. 460 J/kg.K | | Electrical resistivity | approx. 0.91 micro-ohm.m | | Magnetic permeability | approx. 1.001 (non-magnetic, stable after cold work) | At 16-18 um/m.K the alloy expands roughly 45 % more than H13. On a 600 mm liner at 500 degC that is close to 2 mm of extra growth - design the fits for it or the tooling will nip. --- ## 8. Why 1.2779 is chosen for extrusion tooling H13 (1.2344) over-tempers above about 550 degC. In copper and brass extrusion the billet leaves the container at 700-900 degC, so tool-steel tooling softens and creeps out of tolerance within a shift. 1.2779 is austenitic and hardened by gamma-prime precipitates stable to roughly 700 degC. - Hot yield strength: still approx. 560-620 MPa proof at 650 degC - Creep resistance: boron-strengthened grain boundaries give 100+ h at 650 degC under 379 MPa - No scaling: 15 % Cr keeps the tool face clean in air to approx. 800 degC - Non-magnetic and tough from -196 degC to 700 degC, no ductile-to-brittle transition --- ## 9. Alloy selection and relative cost | Alloy | Temperature ceiling | Rp0.2 at 20 degC | Relative cost/kg | Choose when | |---|---|---|---|---| | H13 / 1.2344 | approx. 540 degC | approx. 1,400 MPa | 1x (index) | Aluminium extrusion dies, hot work below 550 degC | | 17-4PH | approx. 300 degC | approx. 1,100 MPa | 1.5-2x | Strength near ambient, magnetic acceptable | | **1.2779 / A-286** | **approx. 700 degC** | approx. 720 MPa | **4-6x** | **Copper/brass extrusion tooling, 550-700 degC bolting, non-magnetic hot parts** | | Incoloy 901 | approx. 760 degC | approx. 830 MPa | 6-9x | When 700 degC is marginal | | Inconel X-750 | approx. 815 degC | approx. 780 MPa | 8-12x | Springs, fasteners, rings above 700 degC | | Nimonic 80A | approx. 815 degC | approx. 700 MPa | 9-13x | Exhaust valves, turbine hardware | | Waspaloy | approx. 870 degC | approx. 800 MPa | 12-18x | Turbine discs and shafts | Cost index is for forged and heat-treated material and moves with the nickel price. --- ## 10. Forging practice 1. **Start from remelted stock.** ESR standard; VIM + VAR for aerospace specifications. 2. **Soak** at 1120-1150 degC, about one hour per 25 mm of section. Under-soaking is the most common cause of centre bursting. 3. **Forge or ring roll**, heavy steady reductions, minimum 4:1 total ratio. **Stop above 950-980 degC** and reheat - hot ductility falls away sharply below that and the surface tears. 4. **Final pass >= 20 % reduction.** A light finishing pass gives critical strain and coarse duplex grain that no heat treatment will fix. 5. **Air cool**, then solution treat and age as a separate operation. --- ## 11. Heat treatment routes | Route | Solution | Ageing | Use when | |---|---|---|---| | Standard (high strength) | 900-930 degC, 1-2 h, oil/water quench | 700-730 degC, 16 h, air cool | Bolting, shafts, general forgings | | High solution (creep) | 975-985 degC, 1 h, quench | 700-730 degC, 16 h, air cool | Turbine and extrusion tooling above 600 degC | | Class D (A453) | 900-930 degC, quench | 700-730 degC, 16 h + controlled cool | 725 MPa min proof strength specified | Ageing produces a small repeatable contraction. Rough machine before ageing, finish after - typically 3-6 mm allowance on diameter for rings. --- ## 12. Machining and welding Machinability approx. 12-15 % of free-machining steel. Starting values, aged condition, coated carbide, flood coolant: | Operation | vc | Feed | Depth of cut | |---|---|---|---| | Rough turning | 30-45 m/min | 0.25-0.40 mm/rev | 2.5-5.0 mm | | Finish turning | 45-60 m/min | 0.10-0.20 mm/rev | 0.5-1.5 mm | | Face milling | 25-40 m/min | 0.10-0.18 mm/tooth | <= 4 mm | | End milling | 20-35 m/min | 0.05-0.12 mm/tooth | <= 0.5 x D | | Drilling, carbide | 15-25 m/min | 0.08-0.18 mm/rev | - | | Drilling, HSS-Co | 6-10 m/min | 0.05-0.15 mm/rev | - | | Parting / grooving | 20-30 m/min | 0.05-0.12 mm/rev | - | | Threading | 20-30 m/min | - | decreasing passes | | Tapping | 3-5 m/min | - | - | | Grinding | - | - | <= 0.02 mm/pass | The alloy work-hardens under a rubbing tool. Rigid setups, sharp positive-rake carbide, heavy feed at low surface speed, and never let the tool dwell. **Welding:** weld in the *solution treated* condition with matching A-286 filler (AMS 5804 / 5853), GTAW, low heat input, interpass below approx. 150 degC, then re-solution treat and age. Fully aged 1.2779 is sensitive to strain-age cracking in the HAZ. Inspect with dye penetrant - the alloy is non-magnetic so MT finds nothing. --- ## 13. Defects and prevention | Defect | Root cause | Control | |---|---|---| | Centre burst / cavity | Billet under-soaked, cold core | Full soak 1120-1150 degC, 1 h per 25 mm | | Surface tearing, laps | Finishing below 950-980 degC | Reheat instead of forging cold | | Coarse or duplex grain | Light final reduction, or solution temperature too high | Final pass >= 20 % reduction | | Low stress-rupture life | Low boron, or wrong solution route | Certify B; use high-solution route when creep governs | | Ti-rich stringers | Non-remelted stock | ESR standard, VAR when specified | | Distortion after ageing | Residual stress, uneven sections | Rough machine before ageing | | Strain-age cracking | Welding fully aged material | Weld solution-treated, then re-solution + age | | Galling on assembly | Austenitic alloy against itself | Silver or MoS2 coating on threads and mating faces | | Over-ageing in service | Sustained service above approx. 700 degC | Respect the 700 degC limit; move to Incoloy 901 or X-750 | --- ## 14. Forged shapes and size envelope **Extrusion tooling:** mandrels, dies, liners, liner holders, die holders, die inserts, pressure pads, dummy blocks, extrusion stems, containers and container sleeves. **General open-die forgings:** seamless rolled rings, forged rings, round bars, shafts and eccentric shafts, sleeves and bushings, discs and blanks, flanges, forged pipes and tubes, tube sheets, blocks, gear and spindle blanks, valve bodies, stems and seat rings, nozzles, manifolds, forged rolls and wheels. | Shape | Size range | |---|---| | Seamless rolled rings | OD 200-3,500 mm; wall >= 30 mm; height <= 1,000 mm | | Round bars | dia. 80-1,200 mm; length <= 8,000 mm | | Discs / blanks | dia. <= 2,000 mm; thickness <= 600 mm | | Hollow / sleeves | OD <= 1,500 mm; ID >= 100 mm | | Blocks | <= 2,000 x 1,000 x 600 mm | | Single-piece weight | 20 kg - 25,000 kg | Weight formulas at 7.94 g/cm3 (dimensions in mm, result in kg): - Round bar / disc: `pi/4 x D^2 x L x 7.94 / 1,000,000` - Ring / sleeve: `pi/4 x (OD^2 - ID^2) x H x 7.94 / 1,000,000` - Block: `L x W x H x 7.94 / 1,000,000` An interactive calculator is at https://www.steelforgepieces.com/Nickel-Alloy/1.2779.html#calculator --- ## 15. Industries Aluminium, copper and brass extrusion; gas turbines and aero engines; oil, gas and subsea . power and nuclear; process and pressure equipment; cryogenic and LNG equipment. --- ## 16. Testing, certification and traceability - Chemistry: ladle and product analysis by OES, element by element on the certificate - Mechanical: tensile, Rp0.2, elongation, reduction of area, hardness on test bars processed with the forging after final ageing - Ultrasonic: EN 10228-3, ASTM A388 or SEP 1921 - state class and acceptance level on the order - Surface NDT: dye penetrant. MT not applicable (non-magnetic) - Optional: stress rupture to ASTM A453, impact, grain size to ASTM E112, intergranular corrosion, PMI at despatch - Certification: EN 10204 3.1 standard; 3.2 witnessed by SGS, BV, TUV, LR or DNV - Traceability: heat number hard-stamped or vibro-etched on every piece - Packing: fumigation-free plywood cases or steel pallets, VCI wrapped --- ## 17. Lead time and shipping | Stage | Typical duration | |---|---| | Quotation | Within 24 working hours | | Drawing approval | 1-3 days | | ESR billet | Ex-stock, or 10-15 days | | Forging / ring rolling | 7-12 days | | Solution treat + age | 3-5 days (16 h ageing soak is fixed) | | Machining | 5-15 days | | UT, NDT, certificate | 2-4 days | | **Total** | **25-45 days** | Sea transit from Shanghai / Ningbo: US West Coast 18-24 days; US East Coast 30-38 days . North Europe 30-35 days; Mediterranean 26-32 days; Middle East 18-22 days; SE Asia 7-12 days. Air freight for small tooling 5-8 days door to door. Terms: EXW, FOB, CIF or DAP. --- ## 18. How to order Send a drawing (PDF, DWG or STEP) or rough dimensions with: 1. Grade and standard (1.2779, or the A-286 / 1.4980 specification and class) 2. Dimensions - finished, and rough if known 3. Quantity 4. Delivery condition - as forged, heat treated, rough or finish machined 5. NDT and acceptance level 6. Certificate type - EN 10204 3.1 or 3.2, and which third party 7. Required delivery date and destination port --- ## Supplier **Jiangyin Jiangnan Metal Co., Ltd.** - open-die forging factory - Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China 214423 - Telephone / WhatsApp / WeChat: +86 189 2135 9659 - Email: sales@steelforgepieces.com - Website: https://www.steelforgepieces.com/ - Founded 2009; Minimum order 1 piece; Lead time 25-45 days - Working hours: Mon-Fri 08:30-17:30 China Standard Time (UTC+8) - Port of loading: Shanghai or Ningbo --- ## Standards referenced ASTM A453 / A453M Grade 660; ASTM A638 / A638M Grade 660; EN 10269; EN 10302 . AMS 5525 / 5731 / 5732 / 5734 / 5737 / 5804 / 5853; EN 10204; EN 10228-3; ASTM A388 . SEP 1921; ASTM E112; VdTUV Werkstoffblatt 435/3; GB/T (GH2132) ## How to cite > Jiangyin Jiangnan Metal Co., Ltd. (2026). "1.2779 Forgings - Rolled Rings, Extrusion Tooling > & Bars: technical and supply datasheet for X6NiCrTiMoVB25-15-2 / A-286." Jiangyin, Jiangsu, > China. Last reviewed 4 August 2026. > https://www.steelforgepieces.com/Nickel-Alloy/1.2779.html Values are typical for open-die forged 1.2779 in the solution treated and aged condition and are given for guidance. For design work use the governing specification and confirm requirements on the order.