1.POM,anti-abrasion2.bronze powder layer,high load capacity and anti-abrasion.3.Copper/Tin plating layer,anti-corrosion4.HTB-2DX The product can be used under high load with low speed, rotation, oscillation, and also can be applied in no liquid lubricants environment that switches frequently with load; the part can work with out oil, and will have a long operating life if oil giver; the POM layer ...