Steel 100CrMn6-BH
Heat-treated state
EN 100CrMn6 · GB GCr15SiMn
BH = bainite hardened (austempered ~230 °C), 58–62 HRC
Pick for large rings and shock/contaminated-lubrication service: compressive surface stresses, higher toughness, less distortion than martensitic hardening.
Values for the BH condition
Other 100CrMn6 tempers and conditions
100CrMn6 is listed in 8 conditions; see the grade overview at 100CrMn6.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Standard delivery condition for bars, tubes and rings — soft enough to turn/drill before through hardening. | 410 | 660 | 22 | 200 HB | 44 W/m·K |
Normalized | Used after forging to break up carbide networks and homogenize structure before spheroidizing. | 520 | 900 | 12 | 29 HRC | 6 % IACS |
Hot rolled | Mill-edge stock for forging or ring rolling; hard, unmachined, must be spheroidize annealed before machining. | 550 | 950 | 12 | 31 HRC | 6 % IACS |
Cold drawn | Bright drawn bar with close diameter tolerance and good surface for automatic-lathe parts prior to hardening. | 620 | 780 | 10 | 21 HRC | 6 % IACS |
TH + S2 | For elevated-temperature bearings up to ~200 °C, trading some hardness and load rating for stability. | 1,650 | 1,950 | 1.5 | 57 HRC | 5 % IACS |
TH + S1 | Choose when the bearing runs up to ~150 °C and dimensional stability matters more than peak hardness. | 1,780 | 2,100 | 1 | 59 HRC | 5 % IACS |
BHThis page Bainite hardened (austempered ~230 °C), 58–62 HRC | Pick for large rings and shock/contaminated-lubrication service: compressive surface stresses, higher toughness, less distortion than martensitic hardening. | 1,820 | 2,150 | 2 | 60 HRC | 5 % IACS |
through hardened (830–860 °C oil/salt quench) + tempered 160–180 °C | Standard finished bearing condition: maximum contact-fatigue life and wear resistance for service below ~120 °C. | 1,900 | 2,250 | 0.5 | 62 HRC | 36 W/m·K |
What is 100CrMn6-BH?
100CrMn6-BH is 100CrMn6 heat treated to BH — pick for large rings and shock/contaminated-lubrication service: compressive surface stresses, higher toughness, less distortion than martensitic hardening. 100CrMn6-BH has a yield strength of 1,820 MPa (264 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Elongation at break is 2% and the elastic modulus is 210 GPa (30.5 Msi). 100CrMn6-BH has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,400°C (2,552 °F). +A is the default condition FabDigit quotes; BH is available on request or by drawing note.
Advantages
- High strength — 1,820 MPa (264 ksi), better than 99% of steel grades
- Polishes to a fine finish — 85/100, better than 99% of steel grades
Limitations
- Difficult to machine — 5/100, 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 ductility — 2%, worse than 99% of steel grades
- Low fracture toughness — 24 MPa·√m (21.8 ksi·√in), worse than 98% of steel grades
100CrMn6-BH properties
Typical room-temperature values for 100CrMn6-BH; 21 are specific to this condition. Other listed values are 100CrMn6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
100CrMn6-BH has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
100CrMn6-BH has a yield strength of 1,820 MPa (264 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Elongation at break is 2% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
100CrMn6-BH is rated for continuous service to 180°C (356 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
100CrMn6-BH conducts electricity at 5 % IACS, worse than 82% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 100CrMn6-BH takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability7
100CrMn6-BH's machinability is not recommended (5/100, worse than 100% of steel grades); weldability not recommended (5/100); formability not recommended (2/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 100CrMn6-BH
Is 100CrMn6 easy to machine?
Machine only in the spheroidize-annealed condition with sharp carbide tooling and rigid setups (~35 % of AISI 1212); once hardened above 58 HRC use grinding, honing or CBN hard turning.
Can 100CrMn6 be welded?
Effectively non-weldable (1 %C): if repair is unavoidable, preheat 300–400 °C, use low-hydrogen or Ni-based filler and re-anneal immediately.
Can 100CrMn6 be formed, bent or molded?
Hot forge 1050–850 °C then slow-cool/normalize and spheroidize; cold ring rolling and cold heading only from the fully annealed state.
What surface finishes work on 100CrMn6?
Not anodizable — protect with oil, phosphate, black oxide, zinc or hard chrome; the clean fine-carbide microstructure superfinishes to Ra <0.05 µm raceways.
100CrMn6 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 |
|---|---|---|
| CGB/T 18254 GCr15SiMn: 0.95–1.05 | 0.93 – 1.05 | 1 |
| Si | 0.45 – 0.75 | 0.6 |
| MnEN: 1.00–1.20 | 0.95 – 1.25 | 1.1 |
| Cr | 1.4 – 1.65 | 1.5 |
| Moresidual | ≤ 0.1 | 0.03 |
| Niresidual | ≤ 0.3 | 0.1 |
| Curesidual | ≤ 0.3 | 0.1 |
| P | ≤ 0.03 | 0.01 |
| S≤0.025 in some grades | ≤ 0.02 | 0.01 |
| Ototal oxygen, cleanliness requirement | ≤ 0 | 8×10⁻⁴ |
| Fe | balance | — |
100CrMn6-BH — frequently asked
What is 100CrMn6-BH used for?
100CrMn6-BH is typically used for large bearing rings, heavy-duty rollers and wind turbine bearings. In short: deeper-hardening 100Cr6; 60–64 HRC raceways; large-section bearing steel.
What is the yield strength of 100CrMn6-BH?
100CrMn6-BH has a typical yield strength of 1,820 MPa (264 ksi) and a tensile strength of 2,150 MPa (312 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 100CrMn6-BH easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 100% of steel grades). Machine only in the spheroidize-annealed condition with sharp carbide tooling and rigid setups (~35 % of AISI 1212); once hardened above 58 HRC use grinding, honing or CBN hard turning.
Can 100CrMn6-BH be welded?
Not readily — weldability is rated not recommended (5/100). Effectively non-weldable (1 %C): if repair is unavoidable, preheat 300–400 °C, use low-hydrogen or Ni-based filler and re-anneal immediately.
What surface finishes work on 100CrMn6-BH?
Not anodizable — protect with oil, phosphate, black oxide, zinc or hard chrome; the clean fine-carbide microstructure superfinishes to Ra <0.05 µm raceways.
Can 100CrMn6-BH be formed, bent or molded?
Hot forge 1050–850 °C then slow-cool/normalize and spheroidize; cold ring rolling and cold heading only from the fully annealed state.
What is the maximum service temperature of 100CrMn6-BH?
100CrMn6-BH 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 100CrMn6 +A and 100CrMn6-BH?
+A is the default condition — standard delivery condition for bars, tubes and rings — soft enough to turn/drill before through hardening. BH: pick for large rings and shock/contaminated-lubrication service: compressive surface stresses, higher toughness, less distortion than martensitic hardening. Yield strength is 410 MPa in +A versus 1,820 MPa in BH.
Sources
- EN ISO 683-17 Heat-treatable steels — Part 17: Ball and roller bearing steels — ISO/CEN (2014)
- DIN 17230 / Werkstoff-Nr. 1.3520 (100CrMn6) — DIN (1980)
- GB/T 18254 (GCr15SiMn) — SAC (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys (bearing steels) — ASM International (1990)
- Bearing steel grade data (100Cr6 / 100CrMnSi6-4) — Ovako / Sandvik / Böhler (2022)
- GCr15SiMn — Mysteel / 1688 (2025)
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.