These bearing cover guide rollers feature a two-flange design and a single bearing wheel. They are optimal for medium duty applications such as sliding doors and conveyor transportation. These rollers are available in steel, hardended steel, plastic and stainless steel. They can be used with polished square steel bar for rails. Hardened steel rollers are wear-resistant and prevent damage from intrusion of chips and other debris. Body is made from nickel-plated 1045 steel, heat-treated 4135 steel with a black oxide finish, black polyacetal plastic, or 303 stainless. Bearing and C-type retaining ring are made from steel or stainless steel.