Steel 51CrV4 Hot Rolled
Finish state
EN 51CrV4 · UNS G61500 · AISI/SAE 6150 · JIS SUP10 · GB 50CrVA
Cheapest mill condition for leaf-spring flats and forging stock; scale and decarburised skin must be removed before hardening.
Values for the Hot Rolled condition
Other 51CrV4 tempers and conditions
51CrV4 is listed in 8 conditions; see the grade overview at 51CrV4.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Long sub-critical anneal that rounds the carbides into globular form, giving the lowest hardness and best cold-forming/machining behaviour of this grade. | 380 | 640 | 22 | 190 HB | 46 W/m·K |
High Shearability | Softened delivery condition with hardness held below a set ceiling so bar and wire can be cold-sheared or cropped cleanly without cracking. | 430 | 700 | 18 | 215 HB | 45 W/m·K |
Core Hardened | Bar/rod delivered heat-treated to a specified core-strength (core hardness) band, giving uniform mid-range strength and good machinability before final hardening. | 460 | 720 | 16 | 210 HB | 44 W/m·K |
AnnealedDefault max 248 HB | Standard stock condition for bar and strip that will be machined or formed and then hardened by the customer. | 520 | 800 | 15 | 230 HB | — |
Hot RolledThis page as-rolled bar / flat | Cheapest mill condition for leaf-spring flats and forging stock; scale and decarburised skin must be removed before hardening. | 600 | 950 | 12 | 29 HRC | 6.9 % IACS |
air cooled from ~860 °C | Used to homogenise forgings and refine grain before machining or final hardening. | 650 | 1,000 | 12 | 31 HRC | 6.9 % IACS |
cold drawn / peeled bar | Bright, close-tolerance bar for torsion bars and shafting where light machining follows; residual stress must be considered. | 800 | 950 | 8 | 30 HRC | 6.8 % IACS |
spring temper, tempered ~400–430 °C (≈48–52 HRC) | Full spring hardness for leaf springs, saw/knife blades and hand tools where maximum elastic limit is needed and ductility can be sacrificed. | 1,500 | 1,700 | 6 | 50 HRC | — |
What is 51CrV4 Hot Rolled?
51CrV4 Hot Rolled is 51CrV4 supplied in the Hot Rolled condition — cheapest mill condition for leaf-spring flats and forging stock; scale and decarburised skin must be removed before hardening. 51CrV4 Hot Rolled has a yield strength of 600 MPa (87 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 77% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi). 51CrV4 Hot Rolled 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; Hot Rolled is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 600 MPa (87 ksi), better than 77% of steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
- Difficult to weld — 22/100, worse than 81% of steel grades
51CrV4 Hot Rolled properties
Typical room-temperature values for 51CrV4 Hot Rolled; 22 are specific to this condition. Other listed values are 51CrV4 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
51CrV4 Hot Rolled 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).
Mechanical13
51CrV4 Hot Rolled has a yield strength of 600 MPa (87 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 77% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
51CrV4 Hot Rolled is rated for continuous service to 250°C (482 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
51CrV4 Hot Rolled conducts electricity at 6.9 % IACS, worse than 76% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 51CrV4 Hot Rolled takes about 32 MJ of energy and emits 2.1 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability7
51CrV4 Hot Rolled's machinability is fair (42/100, worse than 73% of steel grades); weldability poor (22/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 51CrV4 Hot Rolled
Is 51CrV4 easy to machine?
Machine in the annealed condition (≈55 % of 1212) with rigid setups and carbide tooling; above 40 HRC switch to CBN/ceramic or grinding.
Can 51CrV4 be welded?
Poor weldability at 0.5 % C — preheat 250–350 °C, low-hydrogen consumables and immediate post-weld temper; avoid welding on finished springs.
Can 51CrV4 be formed, bent or molded?
Cold form or coil only in the annealed/soft state (bend radii ≥3 t), then austenitise 840–870 °C, oil quench and temper 400–520 °C; hot form 850–1050 °C.
What surface finishes work on 51CrV4?
Not anodisable; shot-peen springs for fatigue life, then phosphate + epoxy, zinc or Zn-Ni plating with bake-out at 200 °C to avoid hydrogen embrittlement.
51CrV4 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 | 0.47 – 0.55 | 0.51 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.7 – 1.1 | 0.9 |
| Cr | 0.9 – 1.2 | 1.05 |
| Vgrain refinement, secondary carbides | 0.1 – 0.25 | 0.15 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
51CrV4 Hot Rolled — frequently asked
What is 51CrV4 Hot Rolled used for?
51CrV4 Hot Rolled is typically used for leaf springs, coil springs and springs. In short: vanadium chromium spring bar.
What is the yield strength of 51CrV4 Hot Rolled?
51CrV4 Hot Rolled has a typical yield strength of 600 MPa (87 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 77% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 51CrV4 Hot Rolled easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine in the annealed condition (≈55 % of 1212) with rigid setups and carbide tooling; above 40 HRC switch to CBN/ceramic or grinding.
Can 51CrV4 Hot Rolled be welded?
Not readily — weldability is rated poor (22/100). Poor weldability at 0.5 % C — preheat 250–350 °C, low-hydrogen consumables and immediate post-weld temper; avoid welding on finished springs.
What surface finishes work on 51CrV4 Hot Rolled?
Not anodisable; shot-peen springs for fatigue life, then phosphate + epoxy, zinc or Zn-Ni plating with bake-out at 200 °C to avoid hydrogen embrittlement.
Can 51CrV4 Hot Rolled be formed, bent or molded?
Cold form or coil only in the annealed/soft state (bend radii ≥3 t), then austenitise 840–870 °C, oil quench and temper 400–520 °C; hot form 850–1050 °C.
What is the maximum service temperature of 51CrV4 Hot Rolled?
51CrV4 Hot Rolled 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 51CrV4 Hot Rolled?
Yes — 51CrV4 Hot Rolled 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
- EN 10089 — Hot rolled steels for quenched and tempered springs — CEN (2002)
- EN 10270-2 — Steel wire for mechanical springs: oil hardened and tempered — CEN (2011)
- GB/T 1222 — (50CrVA) — SAC (2016)
- SAE J404 / ASTM A231 (AISI 6150 Cr-V spring steel) — SAE / ASTM (2019)
- 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)
- Cr-V spring steel 1.8159 datasheet — Böhler / Ovako / Saarstahl (2022)
- EN 13906-1 — Cylindrical helical springs, design — CEN (2013)
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.