Steel 32CrMo12 +QT-250 (+QT 160–250 mm)
Heat-treated state
EN 32CrMo12
Largest ruling section covered by EN 10083-3 for this grade; use where toughness matters more than peak strength.
Values for the +QT-250 condition
Other 32CrMo12 tempers and conditions
32CrMo12 is listed in 8 conditions; see the grade overview at 32CrMo12.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Delivery condition for bar/forgings that must be machined or cold worked before final hardening. | 450 | 750 | 20 | 225 HB | — |
+QT-250This page +QT 160–250 mm | Largest ruling section covered by EN 10083-3 for this grade; use where toughness matters more than peak strength. | 620 | 875 | 17 | 26 HRC | — |
Normalized | Grain-refining treatment before final hardening; because the steel is air-hardening it is already fairly strong and hard in this state. | 700 | 1,050 | 12 | 34 HRC | 6 % IACS |
+QT 100–160 mm | Heavy forged shafts and rolls where the 3 % Cr hardenability still gives through-hardening. | 700 | 925 | 16 | 29 HRC | — |
+QTDefault Quenched and tempered | Default stocked condition: best strength/toughness balance for heavy shafts, rotors and press parts. | 780 | 1,000 | 15 | 31 HRC | — |
+QT + gas nitrided | Choose when wear resistance, scuffing resistance and fatigue strength at the surface are needed on a tough Q&T core (3 % Cr gives a hard, deep case). | 780 | 1,000 | 13 | 64 HRC | — |
+QT 16–40 mm | Standard Q&T class for medium bar used in gear blanks and machine shafts. | 820 | 1,050 | 14 | 34 HRC | — |
+QT ≤16 mm | Highest-strength Q&T class for small bars, pins and bolts up to 16 mm ruling section. | 900 | 1,100 | 13 | 36 HRC | — |
What is 32CrMo12 +QT-250?
32CrMo12 +QT-250 is 32CrMo12 heat treated to +QT-250 — largest ruling section covered by EN 10083-3 for this grade; use where toughness matters more than peak strength. 32CrMo12 +QT-250 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 875 MPa (127 ksi) — stronger than 78% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi). 32CrMo12 +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). +QT is the default condition FabDigit quotes; +QT-250 is available on request or by drawing note.
Advantages
- High service temperature — 480°C (896 °F), better than 88% of steel grades
- High strength — 620 MPa (89.9 ksi), better than 78% 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
- Low electrical conductivity — 6.2 % IACS, worse than 78% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
- Poor heat conductor — 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades
32CrMo12 +QT-250 properties
Typical room-temperature values for 32CrMo12 +QT-250; 11 are specific to this condition. Other listed values are 32CrMo12 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
32CrMo12 +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
32CrMo12 +QT-250 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 875 MPa (127 ksi) — stronger than 78% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
32CrMo12 +QT-250 is rated for continuous service to 480°C (896 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
32CrMo12 +QT-250 conducts electricity at 6.2 % IACS, worse than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 32CrMo12 +QT-250 takes about 30 MJ of energy and emits 2.1 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
32CrMo12 +QT-250's machinability is fair (50/100, worse than 53% of steel grades); weldability poor (25/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 32CrMo12 +QT-250
Is 32CrMo12 easy to machine?
Machine in the annealed state where possible; in Q&T at ~300 HB use coated carbide, rigid setups, 80–140 m/min, and finish-grind after hardening or nitriding.
Can 32CrMo12 be welded?
Air-hardening and crack-sensitive (CE ≈ 1.1): preheat 250–350 °C, low-hydrogen consumables, and temper/stress relieve at 600–650 °C immediately after welding; avoid welding on nitrided surfaces.
Can 32CrMo12 be formed, bent or molded?
Hot forge 1100–850 °C with slow furnace cooling; cold forming only in the soft-annealed state and limited to gentle bends.
What surface finishes work on 32CrMo12?
Not anodizable — protect with paint, zinc/manganese phosphate, hard chrome or QPQ; nitriding both hardens and modestly improves corrosion resistance, and the steel polishes to a fine finish.
32CrMo12 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 | 0.28 – 0.35 | 0.32 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.4 – 0.7 | 0.55 |
| P | ≤ 0.03 | — |
| Smax; lower for +S / low-S variants | ≤ 0.04 | — |
| Cr | 2.8 – 3.3 | 3.05 |
| Mo | 0.3 – 0.5 | 0.4 |
| Fe | balance | — |
32CrMo12 +QT-250 — frequently asked
What is 32CrMo12 +QT-250 used for?
32CrMo12 +QT-250 is typically used for heavy-duty shafts, gears and machine components. In short: deep-hardening Cr-Mo steel; nitrides to high hardness; poor weldability.
What is the yield strength of 32CrMo12 +QT-250?
32CrMo12 +QT-250 has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 875 MPa (127 ksi) — stronger than 78% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 32CrMo12 +QT-250 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine in the annealed state where possible; in Q&T at ~300 HB use coated carbide, rigid setups, 80–140 m/min, and finish-grind after hardening or nitriding.
Can 32CrMo12 +QT-250 be welded?
Not readily — weldability is rated poor (25/100). Air-hardening and crack-sensitive (CE ≈ 1.1): preheat 250–350 °C, low-hydrogen consumables, and temper/stress relieve at 600–650 °C immediately after welding; avoid welding on nitrided surfaces.
What surface finishes work on 32CrMo12 +QT-250?
Not anodizable — protect with paint, zinc/manganese phosphate, hard chrome or QPQ; nitriding both hardens and modestly improves corrosion resistance, and the steel polishes to a fine finish.
Can 32CrMo12 +QT-250 be formed, bent or molded?
Hot forge 1100–850 °C with slow furnace cooling; cold forming only in the soft-annealed state and limited to gentle bends.
What is the maximum service temperature of 32CrMo12 +QT-250?
32CrMo12 +QT-250 is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10083-3 Steels for quenching and tempering — Part 3: Alloy steels — CEN (2006)
- EN 10250-3 Open die steel forgings — Alloy special steels — CEN (1999)
- EN 10085 Nitriding steels — CEN (2001)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4A: Steel Heat Treating Fundamentals and Processes — ASM International (2013)
- Q&T and nitriding steel bar datasheets (1.7361 / 32CrMo12) — European long-products mills (2023)
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.