Steel 60Si2Mn · heat-treated state
Steel 60Si2Mn Q&T
Properties of the Q&T condition, compared with the other 60Si2Mn tempers.
The standard-specified quench-and-temper state used for acceptance testing and for general high-strength structural parts.
What is 60Si2Mn Q&T?
60Si2Mn Q&T is 60Si2Mn heat treated to Q&T — the standard-specified quench-and-temper state used for acceptance testing and for general high-strength structural parts. 60Si2Mn Q&T has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Elongation at break is 8% and the elastic modulus is 206 GPa (29.9 Msi). 60Si2Mn Q&T has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,420°C (2,588 °F). Annealed is the default condition FabDigit quotes; Q&T is available on request or by drawing note.
Advantages
- High strength — 1,300 MPa (189 ksi), better than 95% of steel grades
Limitations
- Limited ductility — 8%, worse than 95% of steel grades
- Limited formability — 10/100, worse than 94% of steel grades
- Difficult to machine — 25/100, worse than 93% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
60Si2Mn Q&T properties
Typical room-temperature values for 60Si2Mn Q&T — 15 properties are specific to this condition; the rest are grade-level values shared by every 60Si2Mn temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
60Si2Mn Q&T has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 93% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical12
60Si2Mn Q&T has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Elongation at break is 8% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
60Si2Mn Q&T is rated for continuous service to 250°C (482 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
60Si2Mn Q&T has an electrical resistivity of 3×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 60Si2Mn Q&T takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 55% of steel grades. Typical recycled content is 35%.
Manufacturability6
60Si2Mn Q&T's machinability is poor (25/100, worse than 93% of steel grades); weldability poor (20/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 60Si2Mn tempers and conditions
60Si2Mn is also supplied in 5 other conditions. The full side-by-side table is on the 60Si2Mn overview.
- AnnealedDefaultStandard stocked condition for machining, cold forming and blanking before final quench-and-temper.480 MPa yield · 255 HB
- Hardened & TemperedFinal spring condition: maximum elastic limit and relaxation resistance for leaf, coil and disc springs; usually shot-peened afterwards.1,600 MPa yield · 48 HRC
- Q&TThe standard-specified quench-and-temper state used for acceptance testing and for general high-strength structural parts.1,300 MPa yield · 44 HRC
Working with 60Si2Mn Q&T
Is 60Si2Mn easy to machine?
Machine only in the annealed (≤302 HBW) state — the high silicon is abrasive, so use rigid setups, coated carbide and moderate speeds; grind after hardening for final size.
Can 60Si2Mn be welded?
Poor: 0.6 %C gives hard, crack-sensitive HAZ — avoid welding on springs; if unavoidable use 200–350 °C preheat, low-hydrogen filler and immediate post-weld temper.
Can 60Si2Mn be formed, bent or molded?
Cold form or coil in the annealed/cold-drawn state with generous bend radii, or hot form at 900–1050 °C; then oil quench 860–880 °C and temper 400–480 °C to the required hardness.
What surface finishes work on 60Si2Mn?
Shot peen springs for fatigue life, then phosphate + paint, powder coat or zinc/e-coat; bake after any electroplating to avoid hydrogen embrittlement — no anodising.
60Si2Mn 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 | 1.5 – 2 | 1.75 |
| Mn | 0.6 – 0.9 | 0.75 |
| Crresidual | ≤ 0.35 | — |
| Niresidual | ≤ 0.35 | — |
| Curesidual | ≤ 0.25 | — |
| P≤0.025 for grade 60Si2MnA | ≤ 0.04 | — |
| S≤0.020 for grade 60Si2MnA | ≤ 0.04 | — |
| Fe | balance | — |
60Si2Mn Q&T — frequently asked
What is 60Si2Mn Q&T used for?
60Si2Mn Q&T is typically used for automotive leaf springs, helical coil springs, railcar and trailer suspension springs, torsion bars, heavy spring washers and clips and clamp and retaining springs. In short: workhorse spring bar.
What is the yield strength of 60Si2Mn Q&T?
60Si2Mn Q&T has a typical yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,450 MPa (210 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 60Si2Mn Q&T easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% of steel grades). Machine only in the annealed (≤302 HBW) state — the high silicon is abrasive, so use rigid setups, coated carbide and moderate speeds; grind after hardening for final size.
Can 60Si2Mn Q&T be welded?
Not readily — weldability is rated poor (20/100). Poor: 0.6 %C gives hard, crack-sensitive HAZ — avoid welding on springs; if unavoidable use 200–350 °C preheat, low-hydrogen filler and immediate post-weld temper.
What surface finishes work on 60Si2Mn Q&T?
Shot peen springs for fatigue life, then phosphate + paint, powder coat or zinc/e-coat; bake after any electroplating to avoid hydrogen embrittlement — no anodising.
Can 60Si2Mn Q&T be formed, bent or molded?
Cold form or coil in the annealed/cold-drawn state with generous bend radii, or hot form at 900–1050 °C; then oil quench 860–880 °C and temper 400–480 °C to the required hardness.
What is the maximum service temperature of 60Si2Mn Q&T?
60Si2Mn Q&T is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 60Si2Mn Q&T?
Yes — 60Si2Mn Q&T 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
- GB/T 1222 (Spring steels) — SAC / (2016)
- GB/T 1222 heat-treatment and mechanical property requirements — SAC (2016)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels (AISI 9260) — ASM International (1990)
- JIS G 4801 SUP7 (spring steel, comparable grade) — JSA (2011)
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.