1. POM 0.03-0.50mm, anti abrasion, low friction coefficient even no oil given. The inside of the bearing are full ofindentions, which need to be filled with grease before installing. 2.Bronze powder layer, 0.2-0.35mm, high load capacity and anti-abrasion, good thermal conductivity, which also further strengthen the combination of the POM layer and steel plate. 3. Low carbon steel, which improved, ...