PTFE composite thrust washers

SKF PTFE composite thrust washers are self-lubricating as well as maintenance-free and provide a long service life due to low friction. Despite of their compact design, these washers can accommodate heavy axial loads and are suitable for relatively slow rotational or oscillating movements. They also have good dimensional stability and thermal conductivity.

PTFE composite washers consist of a sheet steel backing on which a 0,2 to 0,4 mm thick porous layer of tin/bronze is sintered. Furthermore, by a rolling process the pores of the sintered layer are filled with a mixture of PTFE (polytetrafluoroethylene) and molybdenum disulphide additives. This additional 5 to 30 μm thick running-in layer provides an optimum combination of the mechanical properties of the sintered tin/bronze and the good sliding and lubricating properties of the PTFE mixture.

Running-in period
During a short running-in period, minute amounts of the PTFE material from the running-in layer are transferred to the counter surfaces. After this transfer has taken place, the characteristics low friction and wear properties of these washers are reached.