Steel 15CrMn
GB 15CrMn
15CrMn is a low-carbon chromium-manganese case-hardening steel of the GB alloy structural steel family, in which strength comes from carburizing rather than from core alloy content.
Reference datasheet — 15CrMn is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the A condition
15CrMn tempers and conditions
15CrMn is supplied in 6 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
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 | — |
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?
15CrMn is a low-carbon chromium-manganese case-hardening steel of the GB alloy structural steel family, in which strength comes from carburizing rather than from core alloy content. Engineers choose it for medium-duty gears, shafts and bushings that need moderate hardenability at lower cost than Ni-Cr grades; it is stocked as hot-rolled, annealed, normalized and cold-drawn bar. In the soft condition it is about 320 MPa yield, 550 MPa tensile, 22 % elongation and 160 HB, with machinability 58 and formability 60. It has no corrosion resistance and must not be welded after carburizing; 20CrMnTi / 18KhGT is the usual step up for deeper, higher-load cases. 15CrMn 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). 15CrMn has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 81% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
What is 15CrMn used for?
- Medium-duty transmission gears
- Splined shafts
- Sprockets and chain wheels
- Bushings and sleeves
- Pins and pivot shafts
- Cam followers
- Clutch and coupling parts
Limitations
- Low strength — 320 MPa (46.4 ksi), worse than 81% of steel grades
15CrMn properties
Typical room-temperature values for 15CrMn-A; bars are the position among steel grades.
Physical3
15CrMn 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 has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 81% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
15CrMn 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 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 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's machinability is good (58/100, better than 75% of steel grades); weldability good (60/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 15CrMn is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 15CrMn
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.
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 |
What surface finishes work on 15CrMn?
Carburize–quench–temper then grind; unhardened parts need phosphating, black oxide, zinc or nickel plating for corrosion protection.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
How much does 15CrMn cost?
15CrMn is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
15CrMn — frequently asked
What is 15CrMn used for?
15CrMn 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?
15CrMn has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 81% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 15CrMn easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% 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 be welded?
Yes — weldability is rated good (60/100). 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?
Carburize–quench–temper then grind; unhardened parts need phosphating, black oxide, zinc or nickel plating for corrosion protection.
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 is the maximum service temperature of 15CrMn?
15CrMn 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.
How much does 15CrMn cost?
15CrMn is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.