Steel 100CrMnMoSi8-4-6
EN 100CrMnMoSi8-4-6
100CrMnMoSi8-4-6 (1.3539) is a highly alloyed Cr-Mn-Mo-Si through-hardening bearing steel with about 1 %C, giving the deepest hardenability in this bearing steel group plus dimensional-stability tempers (S1–S3).
Reference datasheet — 100CrMnMoSi8-4-6 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
100CrMnMoSi8-4-6 tempers and conditions
100CrMnMoSi8-4-6 is supplied in 8 conditions, soft to hard. +A is the default FabDigit quotes; the values on this page are for it.
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 forged ring blanks — soft enough for turning before hardening. | 430 | 720 | 14 | 220 HB | — |
Soft annealed then cold drawn / peeled-ground bar | Precision bar for small rollers, pins and bushings machined from bar without further softening. | 620 | 800 | 8 | 24 HRC | 4.4 % IACS |
Hot rolled | Mill condition before annealing; very hard and brittle because the alloy air-hardens on cooling — always anneal before machining. | 950 | 1,250 | 6 | 41 HRC | 4.3 % IACS |
Hardened + stabilized ~300 °C, 54–57 HRC | Highest stabilization class of this grade, for bearings and rolls operating near 300 °C. | 1,650 | 1,900 | 2 | 55 HRC | 4 % IACS |
Hardened + stabilized ~250 °C, 56–59 HRC | For hot-running applications to ~250 °C where some hardness is traded for thermal dimensional stability. | 1,750 | 2,000 | 1.5 | 57 HRC | 3.9 % IACS |
Bainite hardened (austempered), 58–62 HRC | Choose for large wind-turbine and rolling-mill bearings needing high toughness, compressive surface stress and low distortion/crack risk. | 1,800 | 2,150 | 2 | 60 HRC | — |
Hardened + dimensionally stabilized ~200 °C, 58–61 HRC | Stabilized for bearings running continuously up to about 200 °C with tight dimensional tolerance. | 1,850 | 2,150 | 1 | 59 HRC | 3.8 % IACS |
Martensitic hardened + tempered ~160 °C, 60–64 HRC | Standard through-hardened bearing condition for maximum contact fatigue capacity in large rings and rollers. | 2,000 | 2,300 | 1 | 62 HRC | — |
What is 100CrMnMoSi8-4-6?
100CrMnMoSi8-4-6 (1.3539) is a highly alloyed Cr-Mn-Mo-Si through-hardening bearing steel with about 1 %C, giving the deepest hardenability in this bearing steel group plus dimensional-stability tempers (S1–S3). It is specified for very large, heavily loaded bearing rings and rollers and supplied as forged rings and heavy bar; annealed properties are near 220 HB with 720 MPa tensile, 430 MPa yield and 14 % elongation. The steel is air-hardening, so it is essentially non-weldable and cracks if quenched from forging; it has no corrosion resistance and is limited to about 200 °C. 100CrMo7-4 suits smaller sections. 100CrMnMoSi8-4-6 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F). 100CrMnMoSi8-4-6 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 720 MPa (104 ksi) — weaker than 51% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
What is 100CrMnMoSi8-4-6 used for?
- Very large rolling bearings
- Heavy machinery bearing rings
- Mill and crusher bearings
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
Limitations
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades
- Difficult to machine — 38/100, worse than 80% of steel grades
100CrMnMoSi8-4-6 properties
Typical room-temperature values for 100CrMnMoSi8-4-6-+A; bars are the position among steel grades.
Physical3
100CrMnMoSi8-4-6 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
100CrMnMoSi8-4-6 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 720 MPa (104 ksi) — weaker than 51% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
100CrMnMoSi8-4-6 is rated for continuous service to 200°C (392 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 80% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
100CrMnMoSi8-4-6 has an electrical resistivity of 3.9×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 100CrMnMoSi8-4-6 takes about 34 MJ of energy and emits 2.5 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
100CrMnMoSi8-4-6's machinability is fair (38/100, worse than 80% of steel grades); weldability not recommended (10/100); formability poor (30/100).
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. 100CrMnMoSi8-4-6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 100CrMnMoSi8-4-6
Is 100CrMnMoSi8-4-6 easy to machine?
Turn/drill only in the spheroidize-annealed condition with coated carbide and rigid setups; after hardening the part is finished by grinding, honing or hard turning with CBN.
Can 100CrMnMoSi8-4-6 be welded?
Essentially non-weldable (~1 %C, air-hardening); if repair is unavoidable use preheat 300–400 °C, low-hydrogen filler and immediate post-weld temper, accepting reduced fatigue life.
Can 100CrMnMoSi8-4-6 be formed, bent or molded?
Hot forge 1100 → 850 °C with slow controlled cooling (air-hardening steel cracks if quenched from forging), then spheroidize anneal ~790 °C; cold forming limited to light coining of annealed stock.
100CrMnMoSi8-4-6 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 |
| Si | 0.4 – 0.6 | 0.5 |
| Mn | 0.8 – 1.1 | 0.95 |
| Cr | 1.8 – 2.05 | 1.9 |
| Mo | 0.5 – 0.6 | 0.55 |
| P | ≤ 0.03 | |
| S | ≤ 0.02 | |
| Curesidual, max | ≤ 0.3 | |
| Niresidual, max | ≤ 0.3 | |
| Fe | balance |
What surface finishes work on 100CrMnMoSi8-4-6?
No anodizing; protect with oil, phosphate, black oxide or thin dense chrome, and grind/lap raceways to Ra < 0.1 µm for full bearing life.
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
Equivalent designations
Standards and trade names that resolve to Steel 100CrMnMoSi8-4-6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.3539
How much does 100CrMnMoSi8-4-6 cost?
100CrMnMoSi8-4-6 is a standard-cost steel ($$), cheaper than about 71% 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.
100CrMnMoSi8-4-6 — frequently asked
What is 100CrMnMoSi8-4-6 used for?
100CrMnMoSi8-4-6 is typically used for very large rolling bearings, heavy machinery bearing rings and mill and crusher bearings. In short: deepest-hardening bearing grade; air-hardening, dimensionally stable; for very large bearings.
What is the yield strength of 100CrMnMoSi8-4-6?
100CrMnMoSi8-4-6 has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 720 MPa (104 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 100CrMnMoSi8-4-6 easy to machine?
Not especially — machinability is rated fair (38/100, worse than 80% of steel grades). Turn/drill only in the spheroidize-annealed condition with coated carbide and rigid setups; after hardening the part is finished by grinding, honing or hard turning with CBN.
Can 100CrMnMoSi8-4-6 be welded?
Not readily — weldability is rated not recommended (10/100). Essentially non-weldable (~1 %C, air-hardening); if repair is unavoidable use preheat 300–400 °C, low-hydrogen filler and immediate post-weld temper, accepting reduced fatigue life.
What surface finishes work on 100CrMnMoSi8-4-6?
No anodizing; protect with oil, phosphate, black oxide or thin dense chrome, and grind/lap raceways to Ra < 0.1 µm for full bearing life.
Can 100CrMnMoSi8-4-6 be formed, bent or molded?
Hot forge 1100 → 850 °C with slow controlled cooling (air-hardening steel cracks if quenched from forging), then spheroidize anneal ~790 °C; cold forming limited to light coining of annealed stock.
What is the maximum service temperature of 100CrMnMoSi8-4-6?
100CrMnMoSi8-4-6 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 100CrMnMoSi8-4-6 +A and 100CrMnMoSi8-4-6-M60?
+A is the default condition — standard delivery condition for bars, tubes and forged ring blanks — soft enough for turning before hardening. M60: standard through-hardened bearing condition for maximum contact fatigue capacity in large rings and rollers. Yield strength is 430 MPa in +A versus 2,000 MPa in M60.
How much does 100CrMnMoSi8-4-6 cost?
100CrMnMoSi8-4-6 is a standard-cost steel ($$), cheaper than about 71% 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
- ISO 683-17 — Heat-treatable steels, alloy steels and free-cutting steels: Ball and roller bearing steels — ISO (2014)
- DIN EN ISO 683-17 / Werkstoff-Nr. 1.3539 — DIN (2015)
- Bearing steel grades for large bearings (100CrMnMoSi8-4-6) — Ovako / Saarstahl / Gerdau special steel (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Rolling Bearing Analysis / bearing steel metallurgy chapters — Wiley / SKF technical literature (2007)
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.