Steel 40CrMoV4-6 +QT (Quenched and tempered)
Heat-treated state · default condition
EN 40CrMoV4-6
Standard supply condition for high-temperature bolting, shafts and highly loaded forgings.
Values for the +QT condition
Other 40CrMoV4-6 tempers and conditions
40CrMoV4-6 is listed in 5 conditions; see the grade overview at 40CrMoV4-6.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Delivery condition for rough machining, deep drilling or cold work before final hardening. | 480 | 760 | 20 | 230 HB | — |
Normalized | Grain-refined intermediate state for forgings prior to quench and temper. | 600 | 900 | 16 | 26 HRC | 7.9 % IACS |
+QTDefaultThis page Quenched and tempered | Standard supply condition for high-temperature bolting, shafts and highly loaded forgings. | 800 | 1,000 | 14 | 32 HRC | — |
+QT + gas/plasma nitrided surface | Use when a tough Q&T core must carry a wear- and scuffing-resistant 900–1100 HV nitrided case (V-bearing steel nitrides very well). | 800 | 1,000 | 13 | 66 HRC | — |
+QT high strength | Choose for small cross-sections needing maximum strength; toughness and elevated-temperature stability are reduced. | 1,000 | 1,200 | 11 | 38 HRC | — |
What is 40CrMoV4-6 +QT?
40CrMoV4-6 +QT is 40CrMoV4-6 heat treated to +QT — standard supply condition for high-temperature bolting, shafts and highly loaded forgings. 40CrMoV4-6 +QT has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). 40CrMoV4-6 +QT 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).
Advantages
- High service temperature — 500°C (932 °F), better than 90% of steel grades
- High strength — 800 MPa (116 ksi), better than 86% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited formability — 20/100, worse than 80% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
40CrMoV4-6 +QT properties
Typical room-temperature values for 40CrMoV4-6 +QT; 16 are specific to this condition. Other listed values are 40CrMoV4-6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
40CrMoV4-6 +QT 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
40CrMoV4-6 +QT has a yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
40CrMoV4-6 +QT is rated for continuous service to 500°C (932 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
40CrMoV4-6 +QT 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 40CrMoV4-6 +QT takes about 31 MJ of energy and emits 2.1 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
40CrMoV4-6 +QT's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (25/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 40CrMoV4-6 +QT
Is 40CrMoV4-6 easy to machine?
Machine in +A (≤248 HB) where possible; in +QT at ~300 HB use rigid setups, coated carbide, 80–140 m/min and positive rake to control work hardening.
Can 40CrMoV4-6 be welded?
Poor weldability — high carbon equivalent; preheat 250–350 °C, low-hydrogen matching Cr-Mo-V consumables and immediate PWHT/temper below the last tempering temperature.
Can 40CrMoV4-6 be formed, bent or molded?
Hot forge 1100–850 °C with slow cooling; cold forming only in the annealed state and limited to gentle bends.
What surface finishes work on 40CrMoV4-6?
Not anodizable; protect with phosphate + oil, black oxide, zinc-flake or electroless nickel, or nitride for wear surfaces (watch hydrogen embrittlement — bake after plating).
40CrMoV4-6 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 | 0.36 – 0.44 | 0.4 |
| Si | 0.15 – 0.35 | 0.25 |
| Mn | 0.4 – 0.7 | 0.55 |
| P | ≤ 0.03 | — |
| Smax (bolting quality) | ≤ 0.02 | — |
| Cr | 0.9 – 1.2 | 1.05 |
| Mo | 0.5 – 0.65 | 0.55 |
| Vsecondary hardening / temper resistance | 0.25 – 0.35 | 0.3 |
| Fe | balance | — |
40CrMoV4-6 +QT — frequently asked
What is 40CrMoV4-6 +QT used for?
40CrMoV4-6 +QT is typically used for high-strength shafts and gears, aerospace structural fittings, tooling and dies and highly stressed fasteners. In short: tempering resistant to 500 °C; nitrides well; stronger than 42CrMo4.
What is the yield strength of 40CrMoV4-6 +QT?
40CrMoV4-6 +QT has a typical yield strength of 800 MPa (116 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 86% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is 40CrMoV4-6 +QT easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in +A (≤248 HB) where possible; in +QT at ~300 HB use rigid setups, coated carbide, 80–140 m/min and positive rake to control work hardening.
Can 40CrMoV4-6 +QT be welded?
Not readily — weldability is rated poor (25/100). Poor weldability — high carbon equivalent; preheat 250–350 °C, low-hydrogen matching Cr-Mo-V consumables and immediate PWHT/temper below the last tempering temperature.
What surface finishes work on 40CrMoV4-6 +QT?
Not anodizable; protect with phosphate + oil, black oxide, zinc-flake or electroless nickel, or nitride for wear surfaces (watch hydrogen embrittlement — bake after plating).
Can 40CrMoV4-6 +QT be formed, bent or molded?
Hot forge 1100–850 °C with slow cooling; cold forming only in the annealed state and limited to gentle bends.
What is the maximum service temperature of 40CrMoV4-6 +QT?
40CrMoV4-6 +QT is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10269 — Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties — CEN (2013)
- DIN 17240 — Heat-resisting and highly heat-resisting materials for bolts and nuts — DIN (1976)
- EN 10083-3 — Steels for quenching and tempering, alloy steels — CEN (2006)
- 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-Mo-V bolting steel 1.7711 bar datasheet (typical European special-steel producer data) — Saarstahl / Böhler (2021)
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.