Steel 36CrNiMo4 · heat-treated state
Steel 36CrNiMo4 +QT 250
Properties of the +QT 250 condition, compared with the other 36CrNiMo4 tempers.
Largest EN-covered section; choose when part diameter exceeds 160 mm.
What is 36CrNiMo4 +QT 250?
36CrNiMo4 +QT 250 is 36CrNiMo4 heat treated to +QT 250 — largest EN-covered section; choose when part diameter exceeds 160 mm. 36CrNiMo4 +QT 250 has a yield strength of 610 MPa (88.5 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 77% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi). 36CrNiMo4 +QT 250 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). Q&T is the default condition FabDigit quotes; +QT 250 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High strength — 610 MPa (88.5 ksi), better than 77% 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
36CrNiMo4 +QT 250 properties
Typical room-temperature values for 36CrNiMo4 +QT 250 — 8 properties are specific to this condition; the rest are grade-level values shared by every 36CrNiMo4 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
36CrNiMo4 +QT 250 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
36CrNiMo4 +QT 250 has a yield strength of 610 MPa (88.5 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 77% of steel grades. Elongation at break is 16% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
36CrNiMo4 +QT 250 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 µm/m·K (6.67 µin/in·°F).
Electrical2
36CrNiMo4 +QT 250 has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 36CrNiMo4 +QT 250 takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability6
36CrNiMo4 +QT 250's machinability is good (55/100, better than 62% of steel grades); weldability poor (25/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 36CrNiMo4 tempers and conditions
36CrNiMo4 is also supplied in 12 other conditions. The full side-by-side table is on the 36CrNiMo4 overview.
- Q&TDefaultStandard stocked condition: best strength/toughness balance for medium and heavy shafts.780 MPa yield · 32 HRC
- Q&T 38-42 HRCMaximum practical strength band; use only for small sections where toughness margin is acceptable.1,120 MPa yield · 40 HRC
- +QT 16Highest-strength EN class, for small-diameter bar, bolts and pins.980 MPa yield · 39 HRC
- Q&T 32-36 HRCHigher-strength band for heavily loaded shafts and holders still needing decent toughness.930 MPa yield · 34 HRC
- +QT 40Typical class for medium-diameter shafting and highly loaded fasteners.880 MPa yield · 36 HRC
- Q&T 28-32 HRCTough, readily machinable hardness band for general shafting and gear blanks.800 MPa yield · 30 HRC
- +QT 160Heavy forgings and large shafts where mass effect lowers as-quenched hardness.660 MPa yield · 27 HRC
- +QT 250Largest EN-covered section; choose when part diameter exceeds 160 mm.610 MPa yield · 24 HRC
- +NGrain-refined, uniform structure for forgings prior to final quench and temper.560 MPa yield · 25 HRC
- +ADelivery state for bar that will be machined and then heat treated by the customer.450 MPa yield · 220 HB
Working with 36CrNiMo4 +QT 250
Is 36CrNiMo4 easy to machine?
Machine in the annealed or ≤32 HRC condition with rigid setups, carbide tooling and generous coolant; expect ~50 % of AISI 1212 speeds and heavy tool wear above 36 HRC.
Can 36CrNiMo4 be welded?
Weldable only with care: preheat 250–350 °C, low-hydrogen consumables, interpass control and immediate post-weld temper below the last tempering temperature.
Can 36CrNiMo4 be formed, bent or molded?
Hot forge 1100–850 °C then slow cool/normalize; cold forming is limited to the soft-annealed state with generous bend radii.
What surface finishes work on 36CrNiMo4?
Requires protection — oil, phosphate, black oxide, zinc/nickel or hard chrome plating (bake 190–220 °C against hydrogen embrittlement); polishes and nitrides very well.
36CrNiMo4 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 | 0.32 – 0.4 | 0.36 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.5 – 0.8 | 0.65 |
| P | ≤ 0.03 | — |
| S≤0.035 for +S variants; ≤0.025 for controlled-sulphur | ≤ 0.04 | — |
| Cr | 0.9 – 1.2 | 1.05 |
| Mo | 0.15 – 0.3 | 0.22 |
| Ni | 0.9 – 1.2 | 1.05 |
| Fe | balance | — |
36CrNiMo4 +QT 250 — frequently asked
What is 36CrNiMo4 +QT 250 used for?
36CrNiMo4 +QT 250 is typically used for forged drive shafts, gears and pinions, crankshafts and connecting rods, heavy axle shafts, aerospace fittings and high-strength bolts and studs. In short: high-strength Ni-Cr-Mo bar.
What is the yield strength of 36CrNiMo4 +QT 250?
36CrNiMo4 +QT 250 has a typical yield strength of 610 MPa (88.5 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 77% of steel grades. Strength varies by condition: see the 13 listed tempers.
Is 36CrNiMo4 +QT 250 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the annealed or ≤32 HRC condition with rigid setups, carbide tooling and generous coolant; expect ~50 % of AISI 1212 speeds and heavy tool wear above 36 HRC.
Can 36CrNiMo4 +QT 250 be welded?
Not readily — weldability is rated poor (25/100). Weldable only with care: preheat 250–350 °C, low-hydrogen consumables, interpass control and immediate post-weld temper below the last tempering temperature.
What surface finishes work on 36CrNiMo4 +QT 250?
Requires protection — oil, phosphate, black oxide, zinc/nickel or hard chrome plating (bake 190–220 °C against hydrogen embrittlement); polishes and nitrides very well.
Can 36CrNiMo4 +QT 250 be formed, bent or molded?
Hot forge 1100–850 °C then slow cool/normalize; cold forming is limited to the soft-annealed state with generous bend radii.
What is the maximum service temperature of 36CrNiMo4 +QT 250?
36CrNiMo4 +QT 250 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.
Can FabDigit make parts in 36CrNiMo4 +QT 250?
Yes — 36CrNiMo4 +QT 250 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
- EN 10083-3 Steels for quenching and tempering — Alloy steels — CEN (2006)
- EN 10250-3 Open die steel forgings — Alloy special steels — CEN (1999)
- 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)
- Engineering steel 1.6511 / 36CrNiMo4 bar datasheet — Ovako / Lucchini RS (2022)
- GB/T 3077 (35CrNiMo comparison) — SAC (2015)
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.