Stainless Steel 422 · heat-treated state · default condition
Stainless Steel 422 Hardened & Tempered
Properties of the Hardened & Tempered condition, compared with the other 422 tempers.
Standard turbine-blade / high-temperature bolting condition: best balance of strength, creep resistance and toughness to 650 °C.
What is 422 Hardened & Tempered?
422 Hardened & Tempered is 422 heat treated to Hardened & Tempered — standard turbine-blade / high-temperature bolting condition: best balance of strength, creep resistance and toughness to 650 °C. 422 Hardened & Tempered has a yield strength of 860 MPa (125 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 16% and the elastic modulus is 213 GPa (30.9 Msi). 422 Hardened & Tempered has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Advantages
- High strength — 860 MPa (125 ksi), better than 98% of stainless steel grades
- Low embodied carbon — 3.5 kg CO₂/kg, better than 88% of stainless steel grades
- Conducts heat well — 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades
Limitations
- Difficult to weld — 30/100, worse than 89% of stainless steel grades
- Limited ductility — 16%, worse than 88% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Low fracture toughness — 75 MPa·√m (68.3 ksi·√in), worse than 85% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
422 Hardened & Tempered properties
Typical room-temperature values for 422 Hardened & Tempered — 35 properties are specific to this condition; the rest are grade-level values shared by every 422 temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
422 Hardened & Tempered has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
422 Hardened & Tempered has a yield strength of 860 MPa (125 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 16% and the elastic modulus is 213 GPa (30.9 Msi).
Thermal5
422 Hardened & Tempered is rated for continuous service to 650°C (1,202 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 81% of stainless steel grades. Thermal expansion is 11.2 µm/m·K (6.22 µin/in·°F).
Electrical2
422 Hardened & Tempered has an electrical resistivity of 6×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of 422 Hardened & Tempered takes about 53 MJ of energy and emits 3.5 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 40%.
Manufacturability7
422 Hardened & Tempered's machinability is fair (35/100, better than 51% of stainless steel grades); weldability poor (30/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 422 tempers and conditions
422 is also supplied in 4 other conditions. The full side-by-side table is on the 422 overview.
- Hardened & TemperedDefaultStandard turbine-blade / high-temperature bolting condition: best balance of strength, creep resistance and toughness to 650 °C.860 MPa yield · 32 HRC
- H&T 38-42 HRCChoose when maximum room-temperature strength and wear resistance matter more than toughness or long-term 600 °C stability.1,030 MPa yield · 40 HRC
- N&TAir-cooled from austenitizing then tempered; used for heavy forgings and sections where oil quenching risks cracking.790 MPa yield · 32 HRC
- AnnealedSoftest supply condition for machining, straightening or before hardening; not a service condition for high-temperature parts.590 MPa yield · 22 HRC
Working with 422 Hardened & Tempered
Is 422 easy to machine?
Machine in the annealed or high-temper condition with rigid setups, sharp carbide tooling, low speed (~25–45 m/min) and heavy feeds; the W/V carbides are abrasive and work-hardening is significant.
Can 422 be welded?
Weldable only with 400 °C-class preheat, matching or 410NiMo filler, interpass control and mandatory post-weld temper at ~700 °C — otherwise cold cracking of the martensitic HAZ.
Can 422 be formed, bent or molded?
Hot work at 1100–1150 °C with slow cooling and immediate annealing; cold forming is essentially limited to gentle straightening.
What surface finishes work on 422?
Passivate after machining, or apply steam/black-oxide, chromizing or aluminizing for high-temperature oxidation; takes a good mechanical polish but never anodizes.
422 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 | 0.2 – 0.25 | 0.22 |
| Mn | 0.5 – 1 | 0.75 |
| Si | ≤ 0.5 | 0.35 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Cr | 11 – 12.5 | 11.75 |
| Ni | 0.5 – 1 | 0.75 |
| Mo | 0.9 – 1.25 | 1 |
| W | 0.9 – 1.25 | 1 |
| V | 0.2 – 0.3 | 0.25 |
| Fe | balance | — |
422 Hardened & Tempered — frequently asked
What is 422 Hardened & Tempered used for?
422 Hardened & Tempered is typically used for steam turbine blades, high-temperature bolting and studs, valve bodies and stems for steam service, turbine rotor and disc forgings, pump shafts for hot service and compressor components. In short: high-temp martensitic forging.
What is the yield strength of 422 Hardened & Tempered?
422 Hardened & Tempered has a typical yield strength of 860 MPa (125 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 422 Hardened & Tempered easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machine in the annealed or high-temper condition with rigid setups, sharp carbide tooling, low speed (~25–45 m/min) and heavy feeds; the W/V carbides are abrasive and work-hardening is significant.
Can 422 Hardened & Tempered be welded?
Not readily — weldability is rated poor (30/100). Weldable only with 400 °C-class preheat, matching or 410NiMo filler, interpass control and mandatory post-weld temper at ~700 °C — otherwise cold cracking of the martensitic HAZ.
What surface finishes work on 422 Hardened & Tempered?
Passivate after machining, or apply steam/black-oxide, chromizing or aluminizing for high-temperature oxidation; takes a good mechanical polish but never anodizes.
Can 422 Hardened & Tempered be formed, bent or molded?
Hot work at 1100–1150 °C with slow cooling and immediate annealing; cold forming is essentially limited to gentle straightening.
What is the maximum service temperature of 422 Hardened & Tempered?
422 Hardened & Tempered 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.
Can FabDigit make parts in 422 Hardened & Tempered?
Yes — 422 Hardened & Tempered is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A565/A565M — Martensitic Stainless Steel Bars for High-Temperature Service (Grade 616 / S42200) — ASTM International (2019)
- ASTM A276/A479 — Stainless Steel Bars and Shapes — ASTM International (2022)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Unified Numbering System for Metals and Alloys (UNS S42200) — SAE/ASTM (2017)
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.