Hard bearing is soft inside

Nov. 8, 2001
Standard spherical plain bearings use through-hardened 52100 steel for the spherical inner ring and the outer ring.

Standard spherical plain bearings use through-hardened 52100 steel for the spherical inner ring and the outer ring. The steel resists wear, but is somewhat brittle. This makes it easy to fracture the outer ring, a necessary manufacturing step that lets the inner ring slip into the split outer ring. But under harsh loads and sudden impacts, the brittle steel can fracture and break on impact.

To solve this problem, engineers at RBC Bearings in Fairfield, Conn., make their ImpactTuff spherical bearings out of carburized 8620 steel. They case harden the outer surface of the bearing and ring to RC 60, while keeping the inner core relatively ductile at RC 40. This lets the outer shell take the brunt of the impact, while the softer inner core absorbs and distributes the load to prevent cracks and fracturing. A patented notch machined in the outer ring permits controlled fracturing of the ring, which facilitates bearing assembly.

Sponsored Recommendations

Sept. 16, 2025
From robotic arms to high-speed conveyors, accuracy matters. Discover how encoders transform motor control by turning motion into real-time datadelivering tighter speed control...
Sept. 16, 2025
Keep high-torque gearboxes running efficiently with external lubrication and cooling systems delivered fast. Flexible configurations, sensor-ready monitoring, and stocked options...
Sept. 16, 2025
Now assembled in the U.S., compact P2.e planetary gear units combine maximum torque, thermal efficiency, and flexible configurations for heavy-duty applicationsavailable faster...
Aug. 22, 2025
Discover how to meet growing customer demands for custom products without overextending your engineering team. Learn how scaling your automation strategy can help you win more...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!