It's based on bronze alloy of a particular formulation with high density, with sintered bronze layer ad its interlayer and the compound of PTPF material and Pb as its surface. It offers the property of good self-lubricating, low wear and low friction, it has made full use of strong points of metals and polymer materials. It’s used in steel metallurgical industry, such as those used in roller grooves of successive casting machine, cement grout pumps and spiral conveyers for cement, etc.