Steel 100CrMnSi6-6-BH
Heat-treated state
EN 100CrMnSi6-6
BH = bainite hardened (austempered), 58–62 HRC
Choose bainite hardened (austempered) material at 58–62 HRC for large rings under shock loads or contaminated lubrication, where compressive surface residual stress is wanted.
Values for the BH condition
Other 100CrMnSi6-6 tempers and conditions
100CrMnSi6-6 is listed in 7 conditions; see the grade overview at 100CrMnSi6-6.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ACDefault Spheroidize annealed | Pick the spheroidize (soft) annealed stock condition, ≤217 HB, as the standard stock item for turning, cold heading and subsequent through hardening. | 410 | 680 | 22 | 195 HB | 44 W/m·K |
Spheroidize annealed, peeled / turned-and-polished bar | Use peeled or turned-and-polished annealed bar for large-diameter bearing ring blanks: annealed properties are kept while the decarburized layer and surface defects are removed. | 410 | 680 | 22 | 195 HB | 4.3 % IACS |
Hot rolled | Order as-rolled black bar as the cheapest blank form; the fine pearlitic structure at 290 HB machines poorly, so plan on spheroidize annealing before cutting. | 620 | 1,050 | 10 | 30 HRC | — |
Spheroidize annealed then cold drawn bright bar | Choose spheroidize annealed then cold drawn bright bar for small roller and pin blanks on automatic lathes; tolerance and finish improve while formability falls to 25. | 660 | 820 | 10 | 240 HB | — |
BHThis page Bainite hardened (austempered), 58–62 HRC | Choose bainite hardened (austempered) material at 58–62 HRC for large rings under shock loads or contaminated lubrication, where compressive surface residual stress is wanted. | 1,700 | 2,100 | 1.5 | 60 HRC | 3.9 % IACS |
Through hardened, dimensionally stabilized (temper ≥200 °C), 58–62 HRC | Pick the dimensionally stabilized version, tempered at 200 °C or above to 58–62 HRC, for bearings running long-term at 150–200 °C (S1/S2 stabilization classes). | 1,750 | 2,150 | 1 | 60 HRC | 3.9 % IACS |
Through hardened + tempered 150–180 °C, 60–64 HRC | Specify through hardened and tempered at 150–180 °C for finished bearings: martensite plus residual carbides gives 60 HRC with the best wear and contact fatigue life, but almost no machinability. | 1,900 | 2,300 | 1 | 62 HRC | 34 W/m·K |
What is 100CrMnSi6-6-BH?
100CrMnSi6-6-BH is 100CrMnSi6-6 heat treated to BH — choose bainite hardened (austempered) material at 58–62 HRC for large rings under shock loads or contaminated lubrication, where compressive surface residual stress is wanted. 100CrMnSi6-6-BH has a yield strength of 1,700 MPa (247 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 99% of steel grades. Elongation at break is 1.5% and the elastic modulus is 210 GPa (30.5 Msi). 100CrMnSi6-6-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). +AC is the default condition FabDigit quotes; BH is available on request or by drawing note.
Advantages
- High strength — 1,700 MPa (247 ksi), better than 99% of steel grades
- Polishes to a fine finish — 80/100, better than 97% of steel grades
Limitations
- Difficult to weld — 3/100, worse than 100% of steel grades
- Limited ductility — 1.5%, worse than 99% of steel grades
- Difficult to machine — 9/100, worse than 99% of steel grades
- Limited formability — 4/100, worse than 99% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
100CrMnSi6-6-BH properties
Typical room-temperature values for 100CrMnSi6-6-BH; 22 are specific to this condition. Other listed values are 100CrMnSi6-6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
100CrMnSi6-6-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).
Mechanical15
100CrMnSi6-6-BH has a yield strength of 1,700 MPa (247 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 99% of steel grades. Elongation at break is 1.5% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
100CrMnSi6-6-BH is rated for continuous service to 200°C (392 °F). It conducts heat at 35 W/m·K (20.2 BTU/hr·ft·°F), worse than 75% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
100CrMnSi6-6-BH conducts electricity at 3.9 % IACS, worse than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 100CrMnSi6-6-BH takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability6
100CrMnSi6-6-BH's machinability is not recommended (9/100, worse than 99% of steel grades); weldability not recommended (3/100); formability not recommended (4/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 100CrMnSi6-6-BH
Is 100CrMnSi6-6 easy to machine?
Cut only in the spheroidize-annealed condition (≤217 HB) using coated carbide at low speed and heavier feed. After hardening, CBN hard turning or grinding is required.
Can 100CrMnSi6-6 be welded?
Practically unweldable: high carbon equivalent and strong sensitivity to quench cracking. Use only for repair, with preheat above 300 °C and immediate tempering.
Can 100CrMnSi6-6 be formed, bent or molded?
In the annealed condition it can be cold headed, cold extruded and warm forged into ring blanks. Forge at roughly 1050–850 °C, then slow-cool and spheroidize anneal.
What surface finishes work on 100CrMnSi6-6?
No corrosion resistance — use rust-preventive oil, phosphating, black oxide or chrome plating. Ground and superfinished raceways reach a mirror finish below Ra 0.05 µm.
100CrMnSi6-6 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 | 0.93 – 1.05 | 0.99 |
| Sihigh Si raises hardenability and temper resistance | 0.5 – 0.75 | 0.62 |
| Mn | 1.1 – 1.4 | 1.25 |
| Cr | 1.4 – 1.65 | 1.5 |
| Moresidual element maximum | ≤ 0.1 | — |
| Niresidual element maximum | ≤ 0.3 | — |
| Curesidual element maximum | ≤ 0.3 | — |
| P | ≤ 0.03 | — |
| S | ≤ 0.02 | — |
| Al | ≤ 0.05 | — |
| O15 ppm max (vacuum-degassed bearing steel) | ≤ 0 | — |
| Fe | balance | — |
100CrMnSi6-6-BH — frequently asked
What is 100CrMnSi6-6-BH used for?
100CrMnSi6-6-BH is typically used for large-section bearing rings, heavy rollers, rolling mill bearing races, slewing ring raceways, spherical roller bearing outer rings and large tapered rollers. In short: deepest-hardening bearing grade; for thick bearing rings; very low weldability.
What is the yield strength of 100CrMnSi6-6-BH?
100CrMnSi6-6-BH has a typical yield strength of 1,700 MPa (247 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 99% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 100CrMnSi6-6-BH easy to machine?
Not especially — machinability is rated not recommended (9/100, worse than 99% of steel grades). Cut only in the spheroidize-annealed condition (≤217 HB) using coated carbide at low speed and heavier feed. After hardening, CBN hard turning or grinding is required.
Can 100CrMnSi6-6-BH be welded?
Not readily — weldability is rated not recommended (3/100). Practically unweldable: high carbon equivalent and strong sensitivity to quench cracking. Use only for repair, with preheat above 300 °C and immediate tempering.
What surface finishes work on 100CrMnSi6-6-BH?
No corrosion resistance — use rust-preventive oil, phosphating, black oxide or chrome plating. Ground and superfinished raceways reach a mirror finish below Ra 0.05 µm.
Can 100CrMnSi6-6-BH be formed, bent or molded?
In the annealed condition it can be cold headed, cold extruded and warm forged into ring blanks. Forge at roughly 1050–850 °C, then slow-cool and spheroidize anneal.
What is the maximum service temperature of 100CrMnSi6-6-BH?
100CrMnSi6-6-BH 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 100CrMnSi6-6 +AC and 100CrMnSi6-6-BH?
+AC is the default condition — pick the spheroidize (soft) annealed stock condition, ≤217 HB, as the standard stock item for turning, cold heading and subsequent through hardening. BH: choose bainite hardened (austempered) material at 58–62 HRC for large rings under shock loads or contaminated lubrication, where compressive surface residual stress is wanted. Yield strength is 410 MPa in +AC versus 1,700 MPa in BH.
Sources
- ISO 683-17 Heat-treatable steels — Ball and roller bearing steels — ISO (2014)
- GB/T 18254 (GCr15SiMn) — SAC (2016)
- DIN 17230 Wälzlagerstähle (historical, 1.3519) — DIN (1980)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels — ASM International (1990)
- Bearing steel bar datasheets (Ovako / GCr15SiMn) — producers (2023)
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.