Steel 4615 · heat-treated state
Steel 4615 Carburized
Properties of the Carburized condition, compared with the other 4615 tempers.
The intended service condition: hard wear-resistant case over a tough Ni–Mo core for gears and cams.
What is 4615 Carburized?
4615 Carburized is 4615 heat treated to Carburized — the intended service condition: hard wear-resistant case over a tough Ni–Mo core for gears and cams. 4615 Carburized has a yield strength of 700 MPa (102 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 81% of steel grades. Elongation at break is 13% and the elastic modulus is 205 GPa (29.7 Msi). 4615 Carburized has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; Carburized is available on request or by drawing note.
Advantages
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
Limitations
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Difficult to machine — 15/100, worse than 98% of steel grades
- Limited ductility — 13%, worse than 78% of steel grades
4615 Carburized properties
Typical room-temperature values for 4615 Carburized — 10 properties are specific to this condition; the rest are grade-level values shared by every 4615 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
4615 Carburized has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical13
4615 Carburized has a yield strength of 700 MPa (102 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 81% of steel grades. Elongation at break is 13% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4615 Carburized is rated for continuous service to 180°C (356 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical2
4615 Carburized has an electrical resistivity of 2.3×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 4615 Carburized takes about 29 MJ of energy and emits 2.1 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability7
4615 Carburized's machinability is poor (15/100, worse than 98% of steel grades); weldability good (55/100); formability good (55/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 4615 tempers and conditions
4615 is also supplied in 6 other conditions. The full side-by-side table is on the 4615 overview.
- HRDefaultStandard stock form for parts that will be machined and then carburized or heat treated.350 MPa yield · 163 HB
- CarburizedThe intended service condition: hard wear-resistant case over a tough Ni–Mo core for gears and cams.700 MPa yield · 60 HRC
- Q&TDirect hardening of the low-carbon core for tough, moderately strong shafts and pins where no case is required.680 MPa yield · 25 HRC
- CDChoose for as-drawn dimensional accuracy, straightness and higher yield in screw-machine work.540 MPa yield · 192 HB
- NormalizedUse to homogenize forged or hot-worked stock and give a uniform fine-grain core before carburizing.380 MPa yield · 174 HB
- AnnealedPick for maximum softness and machinability before deep cutting, cold forming or carburizing.340 MPa yield · 149 HB
Working with 4615 Carburized
Is 4615 easy to machine?
Machines like other 0.15 %C alloy carburizing steels (~65 % of 1212); normalized stock cuts cleaner than annealed, use sharp tools and positive rake to avoid gumming.
Can 4615 be welded?
Readily arc-welded in the soft condition with low-hydrogen consumables; preheat 100–200 °C on heavy sections and never weld after carburizing.
Can 4615 be formed, bent or molded?
Good cold formability when annealed (bending, upsetting, thread rolling); hot forge 1100–1200 °C and normalize before carburizing.
What surface finishes work on 4615?
No natural corrosion resistance — finish with black oxide, phosphate plus oil, zinc or nickel plating; grind case-hardened surfaces to size after quenching.
4615 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 | 0.13 – 0.18 | 0.16 |
| Mn | 0.45 – 0.65 | 0.55 |
| Si | 0.15 – 0.35 | 0.25 |
| Ni | 1.65 – 2 | 1.82 |
| Mo | 0.2 – 0.3 | 0.25 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Fe | balance | — |
4615 Carburized — frequently asked
What is 4615 Carburized used for?
4615 Carburized is typically used for gears, forged industrial shafts and pins. In short: carburizing nickel-moly bar.
What is the yield strength of 4615 Carburized?
4615 Carburized has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 4615 Carburized easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Machines like other 0.15 %C alloy carburizing steels (~65 % of 1212); normalized stock cuts cleaner than annealed, use sharp tools and positive rake to avoid gumming.
Can 4615 Carburized be welded?
Yes — weldability is rated good (55/100). Readily arc-welded in the soft condition with low-hydrogen consumables; preheat 100–200 °C on heavy sections and never weld after carburizing.
What surface finishes work on 4615 Carburized?
No natural corrosion resistance — finish with black oxide, phosphate plus oil, zinc or nickel plating; grind case-hardened surfaces to size after quenching.
Can 4615 Carburized be formed, bent or molded?
Good cold formability when annealed (bending, upsetting, thread rolling); hot forge 1100–1200 °C and normalize before carburizing.
What is the maximum service temperature of 4615 Carburized?
4615 Carburized is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4615-HR and 4615-CD?
HR is the default condition — standard stock form for parts that will be machined and then carburized or heat treated. CD: choose for as-drawn dimensional accuracy, straightness and higher yield in screw-machine work. Yield strength is 350 MPa in HR versus 540 MPa in CD.
Can FabDigit make parts in 4615 Carburized?
Yes — 4615 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
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing of Ni-Mo steels) — ASM International (1991)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
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.