BALL: 52100 Bearing Steel, Heat Treated, Hard Chrome Plated, Precision Ground.
RACE:
MIB: Low Carbon Steel, I.D.Protective Coated for Corrosion Resistance, Oil Coated Mfr. Option-Stailess Steel, Heat Treated.
AIB: Alloy Steel, Heat Treated, I.D.Protective Coated for Corrosion Resistance, Oil Coated Mfr. Option-Stailess Steel, Heat Treated.
SIB: Stainless Steel, Heat Treated and Oil Coated.