Forged Bearing Races
Bearing races are the most cleanliness-sensitive forgings we make. Their service life is determined less by hardness than by how few non-metallic inclusions sit beneath the raceway.
Forged bearing races are produced as seamless rolled rings in EN31 bearing steel, hardening to 60–64 HRC. Steel is bought and verified against strict inclusion rating limits because rolling contact fatigue initiates at subsurface inclusions beneath the raceway.
- Diameter
- 100 mm – 1,200 mm
- Material
- EN31 / 100Cr6
- Hardened
- 60 – 64 HRC
- Supply condition
- Spheroidise annealed, 190–220 BHN
- Construction
- Seamless rolled
Forged Bearing Races at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Seamless rolled construction, no weld
- EN31 hardening to 60–64 HRC
- Supplied annealed at 190–220 BHN
- Bought against strict inclusion rating limits
Cleanliness Determines Life
Under rolling contact, peak shear stress occurs just below the raceway surface. An inclusion at that depth initiates the crack that eventually spalls the race. Bearing steel is therefore bought against strict inclusion ratings and verified before forging.
- Peak shear is subsurface
- Inclusions initiate spalling
- Strict inclusion rating limits
- Verified in our own lab
Seamless Rolled Construction
Races are produced as seamless rolled rings so grain runs continuously around the circumference. A welded or plate-cut ring has interrupted grain and a heat-affected zone that would fail under rotating hoop stress.
Race Capability and Supply Condition
Bearing races are the most cleanliness-sensitive forgings we make. Hardness is straightforward to achieve; what decides service life is how few non-metallic inclusions sit beneath the raceway, where peak shear stress occurs under rolling contact.
| Parameter | Range |
|---|---|
| Outside diameter | 100 mm – 1,200 mm |
| Material | EN31 / 100Cr6 |
| Hardened | 60 – 64 HRC |
| Supply condition | Spheroidise annealed, ≈ 190 – 220 HB |
| Construction | Seamless rolled ring |
| Verification | Inclusion rating checked before forging |
Why Races Are Rolled Rather Than Cut
A rolled ring has grain running continuously around its circumference — the orientation hoop stress and rotating contact demand. A ring cut from plate carries the plate's rolling direction across the whole part, and a welded ring adds a heat-affected zone at one discrete location that becomes the failure site. Races are supplied spheroidise annealed so the bearing manufacturer can machine them before applying their own hardening cycle. See why bearing races fail.
People also ask
Why must bearing races be seamless?
A weld or joint creates a heat-affected zone and interrupted grain that becomes the failure site under rotating hoop stress and contact fatigue.
What supply hardness are races delivered at?
Spheroidise annealed at 190–220 BHN so they can be machined, then hardened to 60–64 HRC by the bearing manufacturer or by arrangement.
What ring sizes can you roll?
100 mm to 1,200 mm outside diameter with heights to 300 mm, in rectangular or contoured profiles.
Topics covered on this page
- bearing race
- EN31
- 100Cr6
- seamless rolled ring
- inclusion rating
- rolling contact fatigue
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
Why is bearing steel cleanliness so important?
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Rolling contact fatigue initiates at subsurface inclusions, so cleanliness directly determines bearing life independent of hardness.
What hardness do bearing races reach?
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60–64 HRC after hardening and low tempering in EN31 bearing steel.
Are races supplied machined?
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Proof machined or fully finished to drawing, with concentricity and flatness verified.