Steel 9310 · heat-treated state
Steel 9310 Carburized
Properties of the Carburized condition, compared with the other 9310 tempers.
Choose the final service condition — carburized, quenched and tempered to a 58–62 HRC case over a 32–40 HRC core — for aerospace and helicopter gears; machine before treatment.
What is 9310 Carburized?
9310 Carburized is 9310 heat treated to Carburized — choose the final service condition — carburized, quenched and tempered to a 58–62 HRC case over a 32–40 HRC core — for aerospace and helicopter gears; machine before treatment. 9310 Carburized has a yield strength of 1,030 MPa (149 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 93% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi). 9310 Carburized 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; Carburized is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- High strength — 1,030 MPa (149 ksi), better than 93% of steel grades
Limitations
- Difficult to machine — 8/100, worse than 100% of steel grades
- Difficult to weld — 5/100, worse than 100% of steel grades
- Limited formability — 2/100, worse than 100% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
9310 Carburized properties
Typical room-temperature values for 9310 Carburized — 17 properties are specific to this condition; the rest are grade-level values shared by every 9310 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
9310 Carburized 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
9310 Carburized has a yield strength of 1,030 MPa (149 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 93% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
9310 Carburized is rated for continuous service to 200°C (392 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
9310 Carburized conducts electricity at 6.6 % IACS, worse than 77% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of 9310 Carburized takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
9310 Carburized's machinability is not recommended (8/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (2/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 9310 tempers and conditions
9310 is also supplied in 6 other conditions. The full side-by-side table is on the 9310 overview.
- HRDefaultPick hot-rolled bar as the lowest-cost stock form; with no post-rolling heat treatment hardness and structure are uneven, so normalize or anneal before machining.600 MPa yield · 270 HB
- Q&TUse direct oil quenching from about 843 °C plus a low or medium temper, with no carburizing, for shafts needing 1300 MPa tensile and toughness but no hard wear surface.1,100 MPa yield · 39 HRC
- CarburizedChoose the final service condition — carburized, quenched and tempered to a 58–62 HRC case over a 32–40 HRC core — for aerospace and helicopter gears; machine before treatment.1,030 MPa yield · 60 HRC
- CDUse cold-drawn bright bar for direct turning of small pinions and shafts where tight diameter tolerance, straightness and surface finish matter; elongation falls to 11%.810 MPa yield · 29 HRC
- NormalizedChoose normalizing near 890 °C with air cooling plus a high-temperature temper for uniform structure and high toughness in rough machining; a common AMS 6265 bar supply state.570 MPa yield · 269 HB
- AnnealedPick the subcritical/spheroidize anneal near 630 °C as the standard machining blank: lowest hardness at 235 HB, best cutting and cold forming before carburizing and quenching.450 MPa yield · 235 HB
Working with 9310 Carburized
Is 9310 easy to machine?
Machinability in the annealed or normalized condition is moderate (about 45% of 1212): use coated carbide, moderate cutting speeds and generous coolant, and leave grinding stock on gear teeth. After carburizing and quenching, finish only by grinding or EDM.
Can 9310 be welded?
Weldable but highly hardenable: preheat 150–260 °C, use low-hydrogen or matching Ni-Cr-Mo filler, and temper or stress relieve immediately after welding. Do not weld in carburized areas.
Can 9310 be formed, bent or molded?
Hot forge in the annealed condition at 1100–1200 °C, finish forging above 900 °C and cool slowly; cold forming is moderate with bend radii of at least 3t, followed by stress-relief annealing.
What surface finishes work on 9310?
Not anodizable. After carburizing and grinding use phosphate, black oxide, cadmium or zinc-nickel plating, or shot peening to raise bending fatigue life; bake after electroplating to remove hydrogen.
9310 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 | 0.08 – 0.13 | 0.1 |
| Mn | 0.45 – 0.65 | 0.55 |
| SiAMS 6265 usually limits to 0.20-0.35 | 0.15 – 0.35 | 0.25 |
| Ni | 3 – 3.5 | 3.25 |
| Cr | 1 – 1.4 | 1.2 |
| Mo | 0.08 – 0.15 | 0.12 |
| Paerospace grade AMS 6265 ≤ 0.010 | ≤ 0.03 | — |
| Saerospace grade AMS 6265 ≤ 0.010 | ≤ 0.03 | — |
| Curesidual element | ≤ 0.35 | — |
| Fe | balance | — |
9310 Carburized — frequently asked
What is 9310 Carburized used for?
9310 Carburized is typically used for helicopter gears, crankshafts and drive shafts. In short: heavy-duty case-hardening.
What is the yield strength of 9310 Carburized?
9310 Carburized has a typical yield strength of 1,030 MPa (149 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 93% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 9310 Carburized easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of steel grades). Machinability in the annealed or normalized condition is moderate (about 45% of 1212): use coated carbide, moderate cutting speeds and generous coolant, and leave grinding stock on gear teeth. After carburizing and quenching, finish only by grinding or EDM.
Can 9310 Carburized be welded?
Not readily — weldability is rated not recommended (5/100). Weldable but highly hardenable: preheat 150–260 °C, use low-hydrogen or matching Ni-Cr-Mo filler, and temper or stress relieve immediately after welding. Do not weld in carburized areas.
What surface finishes work on 9310 Carburized?
Not anodizable. After carburizing and grinding use phosphate, black oxide, cadmium or zinc-nickel plating, or shot peening to raise bending fatigue life; bake after electroplating to remove hydrogen.
Can 9310 Carburized be formed, bent or molded?
Hot forge in the annealed condition at 1100–1200 °C, finish forging above 900 °C and cool slowly; cold forming is moderate with bend radii of at least 3t, followed by stress-relief annealing.
What is the maximum service temperature of 9310 Carburized?
9310 Carburized is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 9310-HR and 9310-CD?
HR is the default condition — pick hot-rolled bar as the lowest-cost stock form; with no post-rolling heat treatment hardness and structure are uneven, so normalize or anneal before machining. CD: use cold-drawn bright bar for direct turning of small pinions and shafts where tight diameter tolerance, straightness and surface finish matter; elongation falls to 11%. Yield strength is 600 MPa in HR versus 810 MPa in CD.
Can FabDigit make parts in 9310 Carburized?
Yes — 9310 Carburized 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
- AMS 6265 — Steel Bars, Forgings, Tubing 3.2Ni-1.2Cr-0.12Mo (0.07-0.13C), Vacuum Consumable Electrode Remelted — SAE International (2020)
- AMS 6260 — Steel Bars, Forgings and Tubing 3.2Ni-1.2Cr-0.12Mo, Carburizing Grade — SAE International (2019)
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- EN 10084 — Case hardening steels (14NiCrMo13-4, 1.6657) — CEN (2008)
- GB/T 3077 — (12Cr2Ni4A ) — SAC (2015)
- 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 (carburizing) — ASM International (2013)
- MMPDS-17 low-alloy steel typical property tables — Battelle/FAA (2022)
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.