Steel 40CrV
GB 40CrV
40CrV (equivalent to AISI 6140) is a chromium-vanadium quenched-and-tempered alloy steel; the vanadium refines grain and raises fatigue strength and temper resistance.
Reference datasheet — 40CrV is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT condition
40CrV tempers and conditions
40CrV is supplied in 11 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest supply condition for deep machining, cold cutting and forging stock before final heat treatment. | 400 | 670 | 22 | 197 HB | — |
Hot rolled | Mill supply condition for bar and billet that will be heat treated by the part maker. | 460 | 760 | 16 | 19 HRC | 8.1 % IACS |
Normalized | Uniform fine-grained structure for forgings and as a pre-treatment before quenching; medium strength without full Q&T cost. | 520 | 800 | 17 | 21 HRC | 8.1 % IACS |
Cold drawn | Bright bar with close tolerance and higher yield for shafts and fasteners machined without further heat treatment. | 700 | 850 | 10 | 25 HRC | 7.9 % IACS |
QTDefault Quenched and tempered | Standard commercial quenched and tempered stock — 880 °C oil quench plus 650 °C temper — for shafts and gears needing 810 MPa yield with 13 % elongation and good impact toughness. | 810 | 980 | 13 | 30 HRC | — |
Induction hardened | Wear-resistant surface with tough core for journals, gear teeth and spline shafts. | 810 | 980 | 12 | 56 HRC | 7.5 % IACS |
Q&T to 28–32 HRC | Tough general machine-part hardness; still readily machinable after heat treatment. | 850 | 1,000 | 14 | 30 HRC | 7.8 % IACS |
Q&T to 33–38 HRC | Higher-strength shafts, torsion bars and moderately loaded gears where toughness is still needed. | 1,010 | 1,150 | 12 | 35 HRC | — |
Q&T to 40–45 HRC | High fatigue-strength condition for torsion bars, heavy springs and highly loaded pins. | 1,250 | 1,380 | 9 | 43 HRC | — |
Q&T to 48–52 HRC | Spring/leaf and high-elastic-limit parts; low ductility and notch sensitivity must be designed around. | 1,500 | 1,700 | 7 | 50 HRC | — |
As-quenched (oil, 860–880 °C), untempered | Intermediate state only — must be tempered promptly; quoted for hardenability reference. | 1,550 | 1,980 | 2 | 56 HRC | 5.6 % IACS |
What is 40CrV?
40CrV (equivalent to AISI 6140) is a chromium-vanadium quenched-and-tempered alloy steel; the vanadium refines grain and raises fatigue strength and temper resistance. Engineers use it for shafts, springs and moderately loaded gears, with bar, wire and forgings available annealed, normalized, cold-drawn and in Q&T bands from 28-32 HRC up to 48-52 HRC, plus induction-hardened. In the default Q&T condition it gives 810 MPa yield, 980 MPa tensile, 13 % elongation and 285 HB (30 HRC), with service to 400 °C. It has no corrosion resistance bare and welding needs preheat and post-weld tempering; 42CrMo4 is a more widely stocked alternative at similar strength. 40CrV has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). 40CrV has a yield strength of 810 MPa (117 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 87% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
What is 40CrV used for?
- shafts
- springs
- gears
- tool holders
Advantages
- High strength — 810 MPa (117 ksi), better than 87% of steel grades
Limitations
- Limited ductility — 13%, worse than 78% of steel grades
40CrV properties
Typical room-temperature values for 40CrV-QT; bars are the position among steel grades.
Physical3
40CrV has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
40CrV has a yield strength of 810 MPa (117 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 87% of steel grades. Elongation at break is 13% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
40CrV is rated for continuous service to 400°C (752 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
40CrV conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 40CrV takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability6
40CrV's machinability is fair (50/100, worse than 53% of steel grades); weldability fair (35/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 40CrV is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 40CrV
Is 40CrV easy to machine?
Machine in the annealed or ≤32 HRC Q&T state with carbide tooling and rigid setups; above 40 HRC switch to CBN/ceramic or grinding.
Can 40CrV be welded?
Weldable only with care — preheat 250–350 °C, low-hydrogen consumables, and temper/stress relieve at 550–650 °C after welding; avoid welding fully hardened parts.
Can 40CrV be formed, bent or molded?
Hot forge at 1150–850 °C then normalize; cold bending is limited and should be done annealed with generous radii.
40CrV 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 |
|---|---|---|
| CGB/T 3077 | 0.37 – 0.44 | 0.4 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.5 – 0.8 | 0.65 |
| Cr | 0.8 – 1.1 | 0.95 |
| Vgrain refinement, temper resistance | 0.1 – 0.2 | 0.15 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Niresidual max | ≤ 0.3 | |
| Curesidual max | ≤ 0.25 | |
| Fe | balance |
What surface finishes work on 40CrV?
No natural corrosion protection — use black oxide, phosphate + oil, zinc or hard-chrome plating; grind and shot peen for fatigue-critical surfaces.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 40CrV in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 6140
How much does 40CrV cost?
40CrV is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
40CrV — frequently asked
What is 40CrV used for?
40CrV is typically used for shafts, springs, gears and tool holders. In short: cr-V fatigue-resistant steel; good temper resistance; wide Q&T hardness range.
What is the yield strength of 40CrV?
40CrV has a typical yield strength of 810 MPa (117 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 87% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is 40CrV easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed or ≤32 HRC Q&T state with carbide tooling and rigid setups; above 40 HRC switch to CBN/ceramic or grinding.
Can 40CrV be welded?
With care — weldability is rated fair (35/100). Weldable only with care — preheat 250–350 °C, low-hydrogen consumables, and temper/stress relieve at 550–650 °C after welding; avoid welding fully hardened parts.
What surface finishes work on 40CrV?
No natural corrosion protection — use black oxide, phosphate + oil, zinc or hard-chrome plating; grind and shot peen for fatigue-critical surfaces.
Can 40CrV be formed, bent or molded?
Hot forge at 1150–850 °C then normalize; cold bending is limited and should be done annealed with generous radii.
What is the maximum service temperature of 40CrV?
40CrV is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 40CrV-QT and 40CrV-Q?
QT is the default condition — standard commercial quenched and tempered stock — 880 °C oil quench plus 650 °C temper — for shafts and gears needing 810 MPa yield with 13 % elongation and good impact toughness. Q: intermediate state only — must be tempered promptly; quoted for hardenability reference. Yield strength is 810 MPa in QT versus 1,550 MPa in Q.
How much does 40CrV cost?
40CrV is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GB/T 699 / GB/T 1172 hardness–strength conversion — SAC (1999)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.