These bearing cover guide rollers feature a two-flanged design and double bearings. They are optimal for heavy duty load applications, used for sliding doors or rollers for transport. These rollers can be used with commercial polished square steel bars 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. Bearing and C-type retaining ring are made from steel.