Steel SUP10 Cold Drawn
Supply condition
GB SUP10 · AISI/SAE 6150 · EN 50CrV4, 50CrVA
Choose for close-tolerance bar, torsion-bar and wire blanks needing good surface before hardening.
Values for the Cold Drawn condition
Other SUP10 tempers and conditions
SUP10 is listed in 6 conditions; see the grade overview at SUP10.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft/spheroidize annealed bar and coil for machining and forming | Stock condition for machining, cold forming and pre-heat-treat blanks before quench and temper. | 480 | 780 | 20 | 210 HB | — |
as-rolled bar, flat and coil | Cheapest mill condition for leaf-spring flats and forging stock that will be heat treated later. | 560 | 900 | 14 | 25 HRC | 7.5 % IACS |
austenitised and air cooled, refined grain | Use to homogenise forgings and refine grain before hardening, or where moderate strength suffices. | 660 | 1,000 | 13 | 31 HRC | 7.5 % IACS |
Cold DrawnThis page cold drawn / peeled-ground annealed bar and wire | Choose for close-tolerance bar, torsion-bar and wire blanks needing good surface before hardening. | 800 | 950 | 9 | 28 HRC | 7.4 % IACS |
Higher-temper condition for toughness-critical torsion bars and… | Use where fatigue with impact loading matters more than peak stress (stabiliser bars, heavy leaf springs). | 1,120 | 1,250 | 11 | 40 HRC | 7.2 % IACS |
Quenched and tempered | Standard spring condition: highest usable strength with adequate toughness for leaf, coil and torsion springs. | 1,300 | 1,450 | 9 | 44 HRC | — |
What is SUP10 Cold Drawn?
SUP10 Cold Drawn is SUP10 supplied in the Cold Drawn condition — choose for close-tolerance bar, torsion-bar and wire blanks needing good surface before hardening. SUP10 Cold Drawn has a yield strength of 800 MPa (116 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Elongation at break is 9% and the elastic modulus is 206 GPa (29.9 Msi). SUP10 Cold Drawn 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). Annealed is the default condition FabDigit quotes; Cold Drawn is available on request or by drawing note.
Advantages
- High strength — 800 MPa (116 ksi), better than 86% of steel grades
Limitations
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Limited ductility — 9%, worse than 93% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
SUP10 Cold Drawn properties
Typical room-temperature values for SUP10 Cold Drawn; 22 are specific to this condition. Other listed values are SUP10 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SUP10 Cold Drawn 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).
Mechanical14
SUP10 Cold Drawn has a yield strength of 800 MPa (116 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Elongation at break is 9% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
SUP10 Cold Drawn is rated for continuous service to 180°C (356 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
SUP10 Cold Drawn conducts electricity at 7.4 % IACS, worse than 70% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SUP10 Cold Drawn takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
SUP10 Cold Drawn's machinability is good (58/100, better than 75% of steel grades); weldability poor (25/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SUP10 Cold Drawn
Is SUP10 easy to machine?
Machine in the annealed condition (~55 % of 1212) with rigid setups and carbide at moderate speed; above 40 HRC switch to grinding, CBN or EDM.
Can SUP10 be welded?
Effectively not weldable in the hardened state — high carbon equivalent causes cracking; if unavoidable, preheat 300–350 °C, low-hydrogen consumables and re-quench/temper the whole part.
Can SUP10 be formed, bent or molded?
Cold form or coil only when annealed or as oil-tempered wire; hot forge 1050–1150 °C, finish above 900 °C, slow cool, then harden from 830–870 °C in oil and temper 400–500 °C.
What surface finishes work on SUP10?
No corrosion resistance of its own: shot-peen springs then phosphate + oil, powder coat or paint; avoid acid pickling and electroplating on hardened parts unless baked to relieve hydrogen.
SUP10 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 |
|---|---|---|
| CJIS G4801 SUP10 | 0.47 – 0.55 | 0.51 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.65 – 0.95 | 0.8 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Cr | 0.8 – 1.1 | 0.95 |
| Vgrain refinement, relaxation resistance | 0.15 – 0.25 | 0.2 |
| Cu | ≤ 0.3 | — |
| Fe | balance | — |
SUP10 Cold Drawn — frequently asked
What is SUP10 Cold Drawn used for?
SUP10 Cold Drawn is typically used for coil springs, leaf springs and springs. In short: heavy-duty spring bar.
What is the yield strength of SUP10 Cold Drawn?
SUP10 Cold Drawn has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is SUP10 Cold Drawn easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machine in the annealed condition (~55 % of 1212) with rigid setups and carbide at moderate speed; above 40 HRC switch to grinding, CBN or EDM.
Can SUP10 Cold Drawn be welded?
Not readily — weldability is rated poor (25/100). Effectively not weldable in the hardened state — high carbon equivalent causes cracking; if unavoidable, preheat 300–350 °C, low-hydrogen consumables and re-quench/temper the whole part.
What surface finishes work on SUP10 Cold Drawn?
No corrosion resistance of its own: shot-peen springs then phosphate + oil, powder coat or paint; avoid acid pickling and electroplating on hardened parts unless baked to relieve hydrogen.
Can SUP10 Cold Drawn be formed, bent or molded?
Cold form or coil only when annealed or as oil-tempered wire; hot forge 1050–1150 °C, finish above 900 °C, slow cool, then harden from 830–870 °C in oil and temper 400–500 °C.
What is the maximum service temperature of SUP10 Cold Drawn?
SUP10 Cold Drawn is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in SUP10 Cold Drawn?
Yes — SUP10 Cold Drawn is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G 4801 Spring steels — Japanese Standards Association (2021)
- GB/T 1222 (50CrVA) — SAC (2016)
- SAE J404 / ASTM A231 (6150 Cr-V spring steel) — SAE / ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Machinery's Handbook (machinability ratings, spring design) — Industrial Press (2020)
- Mysteel / 1688 spring steel bar spot quotations (2026)
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.