Steel 100CrMnSi6-6 +AC+C
Supply condition
EN 100CrMnSi6-6
+AC+C = 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.
Values for the +AC+C 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 | — |
+AC+CThis page 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 | — |
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 +AC+C?
100CrMnSi6-6 +AC+C is 100CrMnSi6-6 supplied in the +AC+C condition — 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. 100CrMnSi6-6 +AC+C has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 80% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi). 100CrMnSi6-6 +AC+C 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; +AC+C is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- High strength — 660 MPa (95.7 ksi), better than 80% of steel grades
Limitations
- Difficult to weld — 8/100, worse than 99% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Limited ductility — 10%, worse than 91% of steel grades
- Low electrical conductivity — 4.3 % IACS, worse than 82% of steel grades
100CrMnSi6-6 +AC+C properties
Typical room-temperature values for 100CrMnSi6-6 +AC+C; 14 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 +AC+C 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 +AC+C has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 80% of steel grades. Elongation at break is 10% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
100CrMnSi6-6 +AC+C is rated for continuous service to 200°C (392 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
100CrMnSi6-6 +AC+C conducts electricity at 4.3 % 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 100CrMnSi6-6 +AC+C 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 +AC+C's machinability is fair (50/100, worse than 53% of steel grades); weldability not recommended (8/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 100CrMnSi6-6 +AC+C
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 +AC+C — frequently asked
What is 100CrMnSi6-6 +AC+C used for?
100CrMnSi6-6 +AC+C 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 +AC+C?
100CrMnSi6-6 +AC+C has a typical yield strength of 660 MPa (95.7 ksi) and a tensile strength of 820 MPa (119 ksi) — stronger than 80% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 100CrMnSi6-6 +AC+C easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% 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 +AC+C be welded?
Not readily — weldability is rated not recommended (8/100). 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 +AC+C?
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 +AC+C 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 +AC+C?
100CrMnSi6-6 +AC+C 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.