The BCHN31 is an upward-facing ball roller unit (ball transfer) featuring a nut-lock and flange mounting design, constructed with a stainless steel body and main ball. Model BCHN31 Brand ZH Material Chrome Steel precision P0 P6 P5 P4 Product Description BCHN31 is not a traditional ordinary swivel bearing, but a stainless steel ball roller/ball transfer unit mainly used for material handling, mold worktables, and automated production lines. Company Profile: Zhonghong bearing