Steel 60CrMnA-OT
Heat-treated state
GB 60CrMnA · JIS SUP9A
OT = oil-tempered spring wire / strip
Wire supplied already quenched and tempered so the spring can be cold coiled and only stress-relieved afterwards.
Values for the OT condition
Other 60CrMnA tempers and conditions
60CrMnA is listed in 8 conditions; see the grade overview at 60CrMnA.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Choose for cold coiling, cold shearing, machining of blanks or deep hole drilling before hardening; GB delivery hardness limit ≤ 250 HB. | 430 | 730 | 20 | 217 HB | 45 W/m·K |
Hot rolled | Mill delivery condition for bar and wire rod that will be hot-coiled and heat treated by the spring maker. | 600 | 950 | 14 | 29 HRC | — |
Normalized | Used to refine grain and homogenise structure after forging, before final quench and temper. | 630 | 1,000 | 13 | 31 HRC | 9 % IACS |
Cold drawn | Cold-drawn rounds and wire with better size tolerance and straightness; still requires quench-and-temper for spring duty. | 850 | 1,050 | 8 | 32 HRC | — |
QTDefault Quenched and tempered | Standard property-verification condition of GB/T 1222; balanced strength and toughness for torsion bars and heavy-section spring components. | 1,180 | 1,320 | 11 | 41 HRC | — |
oil quenched + tempered 380–420 °C (spring temper) | Production temper for leaf springs, heavy coil springs and stabiliser bars where maximum elastic limit and sag resistance are needed. | 1,470 | 1,650 | 8 | 46 HRC | — |
quenched, tempered and shot peened | Specify when fatigue life dominates: compressive surface stress from peening (often stress-peened) raises the endurance limit 20–40 %. | 1,470 | 1,650 | 8 | 46 HRC | 7.5 % IACS |
OTThis page Oil-tempered spring wire / strip | Wire supplied already quenched and tempered so the spring can be cold coiled and only stress-relieved afterwards. | 1,520 | 1,700 | 8 | 48 HRC | — |
What is 60CrMnA-OT?
60CrMnA-OT is 60CrMnA heat treated to OT — wire supplied already quenched and tempered so the spring can be cold coiled and only stress-relieved afterwards. 60CrMnA-OT has a yield strength of 1,520 MPa (220 ksi) and a tensile strength of 1,700 MPa (247 ksi) — stronger than 97% of steel grades. Elongation at break is 8% and the elastic modulus is 206 GPa (29.9 Msi). 60CrMnA-OT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). QT is the default condition FabDigit quotes; OT is available on request or by drawing note.
Advantages
- High strength — 1,520 MPa (220 ksi), better than 97% of steel grades
Limitations
- Limited ductility — 8%, worse than 95% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Difficult to machine — 30/100, worse than 89% of steel grades
- Low fracture toughness — 65 MPa·√m (59.2 ksi·√in), worse than 75% of steel grades
60CrMnA-OT properties
Typical room-temperature values for 60CrMnA-OT; 10 are specific to this condition. Other listed values are 60CrMnA reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
60CrMnA-OT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
60CrMnA-OT has a yield strength of 1,520 MPa (220 ksi) and a tensile strength of 1,700 MPa (247 ksi) — stronger than 97% of steel grades. Elongation at break is 8% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
60CrMnA-OT is rated for continuous service to 200°C (392 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).
Electrical3
60CrMnA-OT conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 60CrMnA-OT takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
60CrMnA-OT's machinability is poor (30/100, worse than 89% of steel grades); weldability poor (15/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 60CrMnA-OT
Is 60CrMnA easy to machine?
Machine in the annealed condition (≤250 HB) with carbide tooling and rigid setups; at 44–48 HRC only grinding, hard turning with CBN or EDM is practical.
Can 60CrMnA be welded?
Effectively non-weldable for structural service (CE ≈ 1.0); if unavoidable, preheat 300–350 °C, use low-hydrogen consumables and post-weld temper, accepting local loss of spring properties.
Can 60CrMnA be formed, bent or molded?
Hot coil/forge at 1050–850 °C or cold coil in the annealed/oil-tempered condition, then oil quench 830–860 °C and temper 380–460 °C; guard against decarburisation with controlled atmosphere or generous grinding allowance.
What surface finishes work on 60CrMnA?
Shot peen after tempering for fatigue life, then phosphate-and-oil, powder coat or Zn-flake coating; avoid acid pickling and electroplating on hardened parts or bake at 190–210 °C to relieve hydrogen.
60CrMnA 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 | 0.56 – 0.64 | 0.6 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.7 – 1 | 0.85 |
| Cr | 0.7 – 1 | 0.85 |
| Pmax, GB/T 1222 high-grade limit | ≤ 0.03 | — |
| Smax ('A' = high-quality steel) | ≤ 0.02 | — |
| Curesidual max | ≤ 0.25 | — |
| Niresidual max | ≤ 0.35 | — |
| Fe | balance | — |
60CrMnA-OT — frequently asked
What is 60CrMnA-OT used for?
60CrMnA-OT is typically used for leaf springs, heavy coil springs and clutch springs. In short: deep-hardening spring steel; SUP9A equivalent; heavy-section coil and leaf use.
What is the yield strength of 60CrMnA-OT?
60CrMnA-OT has a typical yield strength of 1,520 MPa (220 ksi) and a tensile strength of 1,700 MPa (247 ksi) — stronger than 97% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 60CrMnA-OT easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine in the annealed condition (≤250 HB) with carbide tooling and rigid setups; at 44–48 HRC only grinding, hard turning with CBN or EDM is practical.
Can 60CrMnA-OT be welded?
Not readily — weldability is rated poor (15/100). Effectively non-weldable for structural service (CE ≈ 1.0); if unavoidable, preheat 300–350 °C, use low-hydrogen consumables and post-weld temper, accepting local loss of spring properties.
What surface finishes work on 60CrMnA-OT?
Shot peen after tempering for fatigue life, then phosphate-and-oil, powder coat or Zn-flake coating; avoid acid pickling and electroplating on hardened parts or bake at 190–210 °C to relieve hydrogen.
Can 60CrMnA-OT be formed, bent or molded?
Hot coil/forge at 1050–850 °C or cold coil in the annealed/oil-tempered condition, then oil quench 830–860 °C and temper 380–460 °C; guard against decarburisation with controlled atmosphere or generous grinding allowance.
What is the maximum service temperature of 60CrMnA-OT?
60CrMnA-OT is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 60CrMnA-QT and 60CrMnA-A?
QT is the default condition — standard property-verification condition of GB/T 1222; balanced strength and toughness for torsion bars and heavy-section spring components. A: choose for cold coiling, cold shearing, machining of blanks or deep hole drilling before hardening; GB delivery hardness limit ≤ 250 HB. Yield strength is 1,180 MPa in QT versus 430 MPa in A.
Sources
- GB/T 1222 Spring Steels — SAC (China) (2016)
- JIS G 4801 Spring Steels (SUP9A) — JISC (2011)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- GB/T 18983 Oil-tempered spring steel wire — SAC (China) (2017)
- SMM / Mysteel spring steel bar price quotations (2025)
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.