For those special applications, QA1's HCOM and HCOM - T Large Bore Series spherical bearings are a great solution. With bore sizes from one to two inches, these spherical bearings are ideal for large applications. Each bearing is made from chromoly steel with an optional self - lubricating PTFE liner. BALL, 52100 Bearing Steel, Heat Treated, Hard Chrome Plated, Precision Ground, , LINER (HCOM - T), PTFE, Self - Lubricating, , RACE, Chromoly Steel, Heat Treated, Protective Coated for Corrosion Resistance.