Stainless Steel 1.4980 STA-900
Precip hard
EN 1.4980 · UNS S66286 · also A-286
STA-900 = solution treated 900 °C + aged 720 °C/16 h
Finer-grain, higher-yield cycle for high-temperature bolting and turbine fasteners where notch strength matters more than creep-rupture ductility.
Values for the STA-900 condition
Other 1.4980 tempers and conditions
1.4980 is listed in 5 conditions; see the grade overview at 1.4980.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest supply condition for forming, deep drawing, machining of complex parts and welding before final aging. | 310 | 690 | 45 | 170 HB | — |
Cold drawn | Cold-drawn bar or wire supplied for cold-heading and secondary forming, or as feedstock to be aged after fabrication. | 690 | 900 | 20 | 25 HRC | 1.9 % IACS |
STADefault Solution treated and aged | Standard commercial condition for bar, forgings and fasteners: ~1000 MPa UTS with good ductility and creep strength to 700 °C. | 700 | 1,000 | 25 | 31 HRC | — |
STA-900This page Solution treated 900 °C + aged 720 °C/16 h | Finer-grain, higher-yield cycle for high-temperature bolting and turbine fasteners where notch strength matters more than creep-rupture ductility. | 760 | 1,035 | 20 | 34 HRC | — |
Cold worked then aged | Choose for 1200 MPa-class bolts, springs and studs where the extra strength from cold work plus γ′ aging is needed at moderate temperature. | 1,000 | 1,240 | 12 | 38 HRC | — |
What is 1.4980 STA-900?
1.4980 STA-900 is 1.4980 in the STA-900 condition — finer-grain, higher-yield cycle for high-temperature bolting and turbine fasteners where notch strength matters more than creep-rupture ductility. 1.4980 STA-900 has a yield strength of 760 MPa (110 ksi) and a tensile strength of 1,035 MPa (150 ksi) — stronger than 94% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 201 GPa (29.2 Msi). 1.4980 STA-900 has a density of 7.92 g/cm³ (0.286 lb/in³), heavier than 77% of stainless steel grades. It melts at 1,370°C (2,498 °F). STA is the default condition FabDigit quotes; STA-900 is available on request or by drawing note.
Advantages
- High strength — 760 MPa (110 ksi), better than 94% of stainless steel grades
Limitations
- Difficult to machine — 18/100, worse than 99% of stainless steel grades
- Poor heat conductor — 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades
- High embodied carbon — 5.8 kg CO₂/kg, worse than 86% of stainless steel grades
- Low electrical conductivity — 1.9 % IACS, worse than 84% of stainless steel grades
- Limited ductility — 20%, worse than 79% of stainless steel grades
1.4980 STA-900 properties
Typical room-temperature values for 1.4980 STA-900; 13 are specific to this condition. Other listed values are 1.4980 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4980 STA-900 has a density of 7.92 g/cm³ (0.286 lb/in³), heavier than 77% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical16
1.4980 STA-900 has a yield strength of 760 MPa (110 ksi) and a tensile strength of 1,035 MPa (150 ksi) — stronger than 94% of stainless steel grades. Elongation at break is 20% and the elastic modulus is 201 GPa (29.2 Msi).
Thermal6
1.4980 STA-900 is rated for continuous service to 650°C (1,202 °F). It conducts heat at 12.6 W/m·K (7.28 BTU/hr·ft·°F), worse than 88% of stainless steel grades. Thermal expansion is 16.4 µm/m·K (9.11 µin/in·°F).
Electrical3
1.4980 STA-900 conducts electricity at 1.9 % IACS, worse than 84% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4980 STA-900 takes about 80 MJ of energy and emits 5.8 kg of CO₂ — more than 89% of stainless steel grades. Typical recycled content is 35%.
Manufacturability7
1.4980 STA-900's machinability is poor (18/100, worse than 99% of stainless steel grades); weldability fair (45/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4980 STA-900
Is 1.4980 easy to machine?
Machine in the solution-treated state when possible; rigid setups, positive-rake carbide or ceramic tooling, low speed (15–25 m/min in STA), heavy feed and flood coolant to avoid work-hardened glaze and rapid notch wear.
Can 1.4980 be welded?
GTAW/EBW with matching or Inconel 82/718 filler in the solution condition, low heat input and no preheat; re-solution treat and age after welding to avoid strain-age (post-weld heat treatment) cracking in restrained joints.
Can 1.4980 be formed, bent or molded?
Cold form or cold head in the solution-treated condition (high work-hardening rate — allow extra power and intermediate anneals); hot work 1100–1150 °C, finish above 950 °C, then solution treat and age.
What surface finishes work on 1.4980?
Passivate per AMS 2700 after machining; electropolish or shot peen for fatigue-critical parts; threaded fasteners are usually silver-plated or coated with dry-film lubricant to prevent galling and high-temperature seizure.
1.4980 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.03 – 0.08 | 0.05 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 2 | 1.3 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cr | 13.5 – 16 | 14.8 |
| Ni | 24 – 27 | 25.5 |
| Mo | 1 – 1.5 | 1.25 |
| Tiγ′ Ni₃(Ti,Al) former | 1.9 – 2.35 | 2.1 |
| V | 0.1 – 0.5 | 0.3 |
| Al | ≤ 0.35 | 0.2 |
| Bgrain-boundary strengthener | 0 – 0.01 | 0.01 |
| Febalance, ~53–55 % | balance | — |
1.4980 STA-900 — frequently asked
What is 1.4980 STA-900 used for?
1.4980 STA-900 is typically used for jet engine fasteners and rings, turbocharger hardware, high-temperature bolting and aerospace structural parts. In short: A-286 under EN number; strength to 700 °C; hardest-machining PH stainless.
What is the yield strength of 1.4980 STA-900?
1.4980 STA-900 has a typical yield strength of 760 MPa (110 ksi) and a tensile strength of 1,035 MPa (150 ksi) — stronger than 94% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4980 STA-900 easy to machine?
Not especially — machinability is rated poor (18/100, worse than 99% of stainless steel grades). Machine in the solution-treated state when possible; rigid setups, positive-rake carbide or ceramic tooling, low speed (15–25 m/min in STA), heavy feed and flood coolant to avoid work-hardened glaze and rapid notch wear.
Can 1.4980 STA-900 be welded?
With care — weldability is rated fair (45/100). GTAW/EBW with matching or Inconel 82/718 filler in the solution condition, low heat input and no preheat; re-solution treat and age after welding to avoid strain-age (post-weld heat treatment) cracking in restrained joints.
What surface finishes work on 1.4980 STA-900?
Passivate per AMS 2700 after machining; electropolish or shot peen for fatigue-critical parts; threaded fasteners are usually silver-plated or coated with dry-film lubricant to prevent galling and high-temperature seizure.
Can 1.4980 STA-900 be formed, bent or molded?
Cold form or cold head in the solution-treated condition (high work-hardening rate — allow extra power and intermediate anneals); hot work 1100–1150 °C, finish above 950 °C, then solution treat and age.
What is the maximum service temperature of 1.4980 STA-900?
1.4980 STA-900 is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4980-STA and 1.4980-ST?
STA is the default condition — standard commercial condition for bar, forgings and fasteners: ~1000 MPa UTS with good ductility and creep strength to 700 °C. ST: softest supply condition for forming, deep drawing, machining of complex parts and welding before final aging. Yield strength is 700 MPa in STA versus 310 MPa in ST.
Sources
- EN 10269 — Steels and nickel alloys for fasteners with specified elevated/low temperature properties (X6NiCrTiMoVB25-15-2, 1.4980) — CEN (2013)
- ASTM A453/A453M — Bolting with Yield Strength 50–120 ksi, Grade 660 Classes A/B/C/D — ASTM (2020)
- AMS 5731 / AMS 5732 / AMS 5737 — Alloy bars, forgings and rings, Fe-25Ni-15Cr-2Ti (A-286) — SAE International (2019)
- AMS 5525 — Steel sheet, strip and plate, corrosion and heat resistant 15Cr-26Ni-1.3Mo-2.1Ti — SAE International (2018)
- ASM Specialty Handbook: Heat-Resistant Materials (A-286 data) — ASM International (1997)
- Metallic Materials Properties Development and Standardization (MMPDS) — A-286 chapter — FAA/Battelle (2023)
- GB/T 14992 / HB 5199 — GH2132 (2019)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.