Steel GCr15SiMn
EN 100CrMn6
GCr15SiMn is a silicon- and manganese-modified high-carbon chromium bearing steel, the higher-hardenability member of the GCr15 family and equivalent to 100CrMn6.
Reference datasheet — GCr15SiMn 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
GCr15SiMn tempers and conditions
GCr15SiMn is supplied in 9 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Order the standard supply condition — fine spheroidal carbides at 195 HB — for turning, cold extrusion and as preparation for final hardening. | 420 | 750 | 22 | 195 HB | — |
Normalized | Normalize after forging to break up carbide networks and refine grain at 300 HB; treat it as a pre-treatment before spheroidize annealing, not a machining condition. | 560 | 980 | 12 | 31 HRC | 7.5 % IACS |
Hot rolled | Take the as-rolled or as-forged blank only as raw stock; hardness reaches 330 HB and is uneven, so spheroidize annealing is required before machining. | 620 | 1,050 | 10 | 35 HRC | 7.5 % IACS |
Cold drawn | Choose annealed-then-cold-drawn bar for close size and good surface when machining small roller and pin blanks directly, accepting 240 HB and low formability. | 700 | 880 | 10 | 22 HRC | 7.5 % IACS |
Q&T stabilized S1 | Pick the ~250 °C stabilizing temper for bearings running to about 200 °C where dimensional stability outranks hardness; 57 HRC reduces hardness and fatigue life. | 1,750 | 2,000 | 3 | 57 HRC | 6 % IACS |
Q&T 61-64 HRC | Specify the standard finished-bearing route — oil quench from 820–840 °C plus 150–180 °C temper — for peak 62 HRC and contact fatigue life in rings and rollers up to 120 °C. | 1,900 | 2,300 | 1 | 62 HRC | 36 W/m·K |
Martempered () + temper, 60-63 HRC | Choose salt-bath martempering plus tempering for thin-wall, large-diameter rings where distortion and quench cracking must be limited, with 61 HRC close to direct quenching. | 1,950 | 2,250 | 1 | 61 HRC | 5.6 % IACS |
Q&T 58-61 HRC | Use the higher 200–230 °C temper on large or heavily loaded rings, trading a little hardness (59 HRC) for toughness and dimensional stability up to 150 °C. | 2,150 | 59 HRC | — | ||
Austempered to lower bainite, 58-62 HRC | Austemper to lower bainite at 58–62 HRC when impact, contaminated lubrication or high compressive surface stress govern — rolling mill, railway and shock-loaded bearings. | 2,200 | 60 HRC | — |
What is GCr15SiMn?
GCr15SiMn is a silicon- and manganese-modified high-carbon chromium bearing steel, the higher-hardenability member of the GCr15 family and equivalent to 100CrMn6. It is used for larger and heavier-duty bearing components that must through-harden, and is supplied as annealed, hot-rolled, normalised or cold-drawn bar, tube and ring blanks at 420 MPa yield, 750 MPa tensile, 22 % elongation and about 195 HB. Carbon near 1 % makes it effectively non-weldable (machinability 42/100, formability 35/100), it is not corrosion resistant, and hardness falls off above the 300 °C limit. GCr15 covers smaller sections at lower cost. GCr15SiMn has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F). GCr15SiMn has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 53% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
What is GCr15SiMn used for?
- Large rolling bearings
- Heavy machinery rollers
- Rail bearings
Advantages
- Polishes to a fine finish — 88/100, better than 100% of steel grades
Limitations
- Difficult to weld — 12/100, worse than 96% of steel grades
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
GCr15SiMn properties
Typical room-temperature values for GCr15SiMn-A; bars are the position among steel grades.
Physical3
GCr15SiMn has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
GCr15SiMn has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 53% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
GCr15SiMn is rated for continuous service to 300°C (572 °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
GCr15SiMn conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of GCr15SiMn takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability7
GCr15SiMn's machinability is fair (42/100, worse than 73% of steel grades); weldability not recommended (12/100); formability fair (35/100).
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. GCr15SiMn is highlighted; hover a dot for its name, or open the interactive family chart.
Working with GCr15SiMn
Is GCr15SiMn easy to machine?
Turn, mill and drill only in the spheroidise-annealed condition (≤229 HB); after hardening restrict work to grinding, CBN hard turning or EDM, and flood-cool grinding to prevent burn and grinding cracks.
Can GCr15SiMn be welded?
With about 1 % C the weldability is very poor and welding should be avoided in principle; if repair is unavoidable, preheat 300–400 °C, use low-hydrogen or nickel-based filler and temper immediately.
Can GCr15SiMn be formed, bent or molded?
In the annealed condition it takes warm upsetting, ring rolling and cold extrusion into raceway blanks; forge at about 1050–1120 °C, finish no lower than 850 °C, then slow-cool plus normalise/spheroidise anneal to break up carbide networks.
GCr15SiMn 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 | 0.95 – 1.05 | 1 |
| Siabove GCr15; raises hardenability and temper stability | 0.45 – 0.75 | 0.6 |
| Mnmarkedly increases hardenability | 0.95 – 1.25 | 1.1 |
| Cr | 1.4 – 1.65 | 1.5 |
| Niresidual element | ≤ 0.3 | |
| Curesidual element; Cu+Ni less than or equal to 0.50 | ≤ 0.25 | |
| Moresidual element | ≤ 0.1 | |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Ooxygen 12 ppm max (quality/high-grade bearing steel) | ≤ 0 | |
| Fe | balance |
What surface finishes work on GCr15SiMn?
Cannot be anodised. Raceways are precision ground and superfinished to a mirror surface, while non-working surfaces are usually black oxided, phosphated, chrome plated or oiled for storage.
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 GCr15SiMn in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 100CrMn6
How much does GCr15SiMn cost?
GCr15SiMn 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.
GCr15SiMn — frequently asked
What is GCr15SiMn used for?
GCr15SiMn is typically used for large rolling bearings, heavy machinery rollers and rail bearings. In short: higher hardenability than GCr15; heavy-section bearing rings; grind-and-superfinish only.
What is the yield strength of GCr15SiMn?
GCr15SiMn has a typical yield strength of 420 MPa (60.9 ksi) and a tensile strength of 750 MPa (109 ksi) — weaker than 53% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is GCr15SiMn easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Turn, mill and drill only in the spheroidise-annealed condition (≤229 HB); after hardening restrict work to grinding, CBN hard turning or EDM, and flood-cool grinding to prevent burn and grinding cracks.
Can GCr15SiMn be welded?
Not readily — weldability is rated not recommended (12/100). With about 1 % C the weldability is very poor and welding should be avoided in principle; if repair is unavoidable, preheat 300–400 °C, use low-hydrogen or nickel-based filler and temper immediately.
What surface finishes work on GCr15SiMn?
Cannot be anodised. Raceways are precision ground and superfinished to a mirror surface, while non-working surfaces are usually black oxided, phosphated, chrome plated or oiled for storage.
Can GCr15SiMn be formed, bent or molded?
In the annealed condition it takes warm upsetting, ring rolling and cold extrusion into raceway blanks; forge at about 1050–1120 °C, finish no lower than 850 °C, then slow-cool plus normalise/spheroidise anneal to break up carbide networks.
What is the maximum service temperature of GCr15SiMn?
GCr15SiMn is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between GCr15SiMn-A and GCr15SiMn-MQ?
A is the default condition — order the standard supply condition — fine spheroidal carbides at 195 HB — for turning, cold extrusion and as preparation for final hardening. MQ: choose salt-bath martempering plus tempering for thin-wall, large-diameter rings where distortion and quench cracking must be limited, with 61 HRC close to direct quenching. Yield strength is 420 MPa in A versus 1,950 MPa in MQ.
How much does GCr15SiMn cost?
GCr15SiMn 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
- ISO 683-17 / DIN EN ISO 683-17 (100CrMn6, 1.3520) — ISO (2014)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Bearing steel grades data (100Cr6 / 100CrMn6) heat treatment and properties — Ovako / SKF (2020)
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.