Steel 35CrMo · heat-treated state
Steel 35CrMo Q&T
Properties of the Q&T condition, compared with the other 35CrMo tempers.
Standard delivered/certified strength condition for shafts, connecting rods and grade 10.9/12.9 fasteners.
What is 35CrMo Q&T?
35CrMo Q&T is 35CrMo heat treated to Q&T — standard delivered/certified strength condition for shafts, connecting rods and grade 10.9/12.9 fasteners. 35CrMo Q&T has a yield strength of 880 MPa (128 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 90% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). 35CrMo Q&T 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). HR is the default condition FabDigit quotes; Q&T is available on request or by drawing note.
Advantages
- High strength — 880 MPa (128 ksi), better than 90% of steel grades
- High service temperature — 480°C (896 °F), better than 88% of steel grades
Limitations
- Limited formability — 15/100, worse than 87% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
35CrMo Q&T properties
Typical room-temperature values for 35CrMo Q&T — 18 properties are specific to this condition; the rest are grade-level values shared by every 35CrMo temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
35CrMo Q&T 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).
Mechanical14
35CrMo Q&T has a yield strength of 880 MPa (128 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 90% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
35CrMo Q&T is rated for continuous service to 480°C (896 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
35CrMo Q&T conducts electricity at 7.8 % IACS, worse than 58% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 35CrMo Q&T takes about 34 MJ of energy and emits 2.3 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
35CrMo Q&T's machinability is fair (42/100, worse than 72% of steel grades); weldability poor (30/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 35CrMo tempers and conditions
35CrMo is also supplied in 10 other conditions. The full side-by-side table is on the 35CrMo overview.
- HRDefaultMost stocked form: as-rolled round bar or plate destined for machining and subsequent quench-and-temper by the part maker.490 MPa yield · 200 HB
- Q&T 40-44 HRCMaximum practical strength band for 35CrMo; use only where impact loading and hydrogen exposure are low.1,230 MPa yield · 42 HRC
- Q&T 34-38 HRCHigher-strength band for gears, high-strength bolting and drill-string components where wear matters more than toughness.1,050 MPa yield · 36 HRC
- Q&TStandard delivered/certified strength condition for shafts, connecting rods and grade 10.9/12.9 fasteners.880 MPa yield · 33 HRC
- Q&T 28-32 HRCTough general-purpose hardness band for machined shafts and NACE MR0175-conscious sour-service parts (≤22 HRC bands aside).860 MPa yield · 30 HRC
- CDChoose for close-tolerance, bright-surface bar used as-supplied in shafting and studs without further heat treatment.680 MPa yield · 250 HB
- CRThin strip/sheet condition for stamped and formed parts that will be hardened after blanking.660 MPa yield · 245 HB
- NormalizedUse for uniform fine-grain structure and moderate strength in large sections that will not be quenched.650 MPa yield · 30 HRC
- N+TCompromise condition for large forgings and pressure parts where oil quenching is impractical.600 MPa yield · 250 HB
- AnnealedPick for maximum machinability and dimensional stability before final heat treatment or for cold forming of blanks.420 MPa yield · 197 HB
Working with 35CrMo Q&T
Is 35CrMo easy to machine?
Machine in the annealed or ≤32 HRC condition with coated carbide, rigid setups and generous coolant; above 38 HRC expect ceramic/CBN finishing or grinding.
Can 35CrMo be welded?
Weldable with low-hydrogen electrodes but requires 200–300 °C preheat, matching Cr-Mo filler and 600–680 °C PWHT to avoid HAZ cold cracking.
Can 35CrMo be formed, bent or molded?
Hot forge at 1150–850 °C then normalize; cold forming only from spheroidize-annealed stock, with generous bend radii.
What surface finishes work on 35CrMo?
No natural corrosion protection — specify oiling, phosphate, zinc or Zn-Ni plating (bake to relieve hydrogen), QPQ/nitriding for wear, or paint.
35CrMo 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 | 0.35 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.4 – 0.7 | 0.55 |
| Cr | 0.8 – 1.1 | 0.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| P≤ 0.025 for high-grade quality | ≤ 0.03 | 0.02 |
| S≤0.025 for high-grade quality | ≤ 0.03 | 0.02 |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.2 | — |
| Fe | balance | — |
35CrMo Q&T — frequently asked
What is 35CrMo Q&T used for?
35CrMo Q&T is typically used for bolts, industrial drive shafts and crankshafts. In short: premium Cr-Mo bar.
What is the yield strength of 35CrMo Q&T?
35CrMo Q&T has a typical yield strength of 880 MPa (128 ksi) and a tensile strength of 1,030 MPa (149 ksi) — stronger than 90% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is 35CrMo Q&T easy to machine?
Not especially — machinability is rated fair (42/100, worse than 72% of steel grades). Machine in the annealed or ≤32 HRC condition with coated carbide, rigid setups and generous coolant; above 38 HRC expect ceramic/CBN finishing or grinding.
Can 35CrMo Q&T be welded?
Not readily — weldability is rated poor (30/100). Weldable with low-hydrogen electrodes but requires 200–300 °C preheat, matching Cr-Mo filler and 600–680 °C PWHT to avoid HAZ cold cracking.
What surface finishes work on 35CrMo Q&T?
No natural corrosion protection — specify oiling, phosphate, zinc or Zn-Ni plating (bake to relieve hydrogen), QPQ/nitriding for wear, or paint.
Can 35CrMo Q&T be formed, bent or molded?
Hot forge at 1150–850 °C then normalize; cold forming only from spheroidize-annealed stock, with generous bend radii.
What is the maximum service temperature of 35CrMo Q&T?
35CrMo Q&T 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.
What is the difference between 35CrMo-HR and 35CrMo-CD?
HR is the default condition — most stocked form: as-rolled round bar or plate destined for machining and subsequent quench-and-temper by the part maker. CD: choose for close-tolerance, bright-surface bar used as-supplied in shafting and studs without further heat treatment. Yield strength is 490 MPa in HR versus 680 MPa in CD.
Can FabDigit make parts in 35CrMo Q&T?
Yes — 35CrMo Q&T 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
- GB/T 699 / GB/T 702 (bar dimensions & delivery condition) — SAC (2016)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (4130/4135/4140 data) — ASM International (1990)
- ASM Handbook Vol.16 — Machining (machinability ratings) — ASM International (1989)
- Cr-Mo structural steel 1.7220 / 34CrMo4 datasheet — Böhler / Deutsche Edelstahlwerke (2021)
- MMPDS-Handbook typical values for 4130/4140 low-alloy steel — Battelle / FAA (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.