1. Product Overview B57Z-8 non-standard deep groove ball bearing, size 57.8×80×13mm, specially matched for automobile gearbox auxiliary shafts. Suffix Z stands for double-sided stamped metal dust shields, without rubber seals, fitted with stamped steel cage and C0 standard clearance. It bears radial load and minor bidirectional axial load, runs stably and quietly at high speed under frequent shift vibration. Made of fully quenched GCr15 steel with precise dimensional