Steel 15CrMn-HR (Hot rolled)
Supply condition
GB 15CrMn
Cheapest stock condition for parts that will be machined then carburized; hardness and structure vary with bar size.
Values for the HR condition
Other 15CrMn tempers and conditions
15CrMn is listed in 6 conditions; see the grade overview at 15CrMn.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard machining condition for gear blanks before carburizing; softest and most dimensionally stable state. | 320 | 550 | 22 | 160 HB | — |
HRThis page Hot rolled | Cheapest stock condition for parts that will be machined then carburized; hardness and structure vary with bar size. | 400 | 650 | 18 | 185 HB | 8 % IACS |
Normalized | Use to refine grain and homogenize forgings/hot-rolled bar before carburizing or heavy machining. | 410 | 640 | 20 | 185 HB | 8 % IACS |
Cold drawn | Bright bar for close-tolerance pins, sleeves and shafts machined with minimal stock removal. | 560 | 720 | 10 | 215 HB | — |
Q&T | Through-hardened direct-quench condition used for small high-strength parts and as the standard's property benchmark (15 mm test bar). | 660 | 860 | 14 | 25 HRC | — |
Carburized + quenched + low tempered | The intended service condition for gears and splines: hard wear-resistant case (0.6–1.2 mm typical) over a tough tempered-martensite core. | 700 | 900 | 11 | 60 HRC | — |
What is 15CrMn-HR?
15CrMn-HR is 15CrMn supplied in the HR condition — cheapest stock condition for parts that will be machined then carburized; hardness and structure vary with bar size. 15CrMn-HR has a yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi). 15CrMn-HR 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). A is the default condition FabDigit quotes; HR is available on request or by drawing note.
15CrMn-HR properties
Typical room-temperature values for 15CrMn-HR; 22 are specific to this condition. Other listed values are 15CrMn reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
15CrMn-HR 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
15CrMn-HR has a yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
15CrMn-HR is rated for continuous service to 350°C (662 °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 µm/m·K (6.67 µin/in·°F).
Electrical3
15CrMn-HR conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 15CrMn-HR takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
15CrMn-HR's machinability is fair (52/100, better than 52% of steel grades); weldability good (58/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 15CrMn-HR
Is 15CrMn easy to machine?
Machine in the annealed/normalized condition with carbide tooling (≈60 % of AISI 1212); leave grinding stock for post-carburizing distortion.
Can 15CrMn be welded?
Weldable in the soft condition with low-hydrogen consumables and 150–200 °C preheat plus stress relief; do not weld carburized surfaces.
Can 15CrMn be formed, bent or molded?
Good hot forging (1150–1200 °C, finish above 850 °C); moderate cold forming/cold heading in the spheroidize-annealed state.
What surface finishes work on 15CrMn?
Carburize–quench–temper then grind; unhardened parts need phosphating, black oxide, zinc or nickel plating for corrosion protection.
15CrMn 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 | 0.12 – 0.18 | 0.15 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 1.1 – 1.4 | 1.25 |
| Cr | 0.4 – 0.7 | 0.55 |
| Pmax, GB/T 3077-2015 (0.035 for older editions/quality grades) | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Niresidual max | ≤ 0.3 | — |
| Curesidual max | ≤ 0.25 | — |
| Fe | balance | — |
15CrMn-HR — frequently asked
What is 15CrMn-HR used for?
15CrMn-HR is typically used for medium-duty transmission gears, splined shafts, sprockets and chain wheels, bushings and sleeves, pins and pivot shafts and cam followers. In short: economical nickel-free gear steel; good machinability, moderate hardenability.
What is the yield strength of 15CrMn-HR?
15CrMn-HR has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 15CrMn-HR easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machine in the annealed/normalized condition with carbide tooling (≈60 % of AISI 1212); leave grinding stock for post-carburizing distortion.
Can 15CrMn-HR be welded?
Yes — weldability is rated good (58/100). Weldable in the soft condition with low-hydrogen consumables and 150–200 °C preheat plus stress relief; do not weld carburized surfaces.
What surface finishes work on 15CrMn-HR?
Carburize–quench–temper then grind; unhardened parts need phosphating, black oxide, zinc or nickel plating for corrosion protection.
Can 15CrMn-HR be formed, bent or molded?
Good hot forging (1150–1200 °C, finish above 850 °C); moderate cold forming/cold heading in the spheroidize-annealed state.
What is the maximum service temperature of 15CrMn-HR?
15CrMn-HR is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 15CrMn-A and 15CrMn CARB?
A is the default condition — standard machining condition for gear blanks before carburizing; softest and most dimensionally stable state. CARB: the intended service condition for gears and splines: hard wear-resistant case (0.6–1.2 mm typical) over a tough tempered-martensite core. Yield strength is 320 MPa in A versus 700 MPa in CARB.
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 — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing practice) — ASM International (1991)
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.