SKF friction bushings: PCM and PWM series

In PCM 050705 E, the letters name the cylindrical bushing and the six digits combine, in pairs, the bore, the outside diameter and the length in millimetres. PCMF 060804 E adds an F: it is the flanged bushing. PCMW 122401.5 E is a thrust washer, and its digits are the bore, the outside diameter and the thickness.

The final letter distinguishes the material of the sliding layer: PCM 081012 M and a PCM ending in E have the same shape and are not equivalent. PWM 202415 belongs to another family of bushings, with a thicker wall, and the same three dimensions in its six digits. In every case, the letters are copied together with the numbers.

A thin-walled bushing takes its final shape when pressed into the housing. That is why the housing bore and the shaft must be within the tolerance stated by the manufacturer: the operating clearance results from them. The shaft surface counts too; a rough shaft wears the sliding layer in a short time.

These bushings cope well with high loads at low speed and reciprocating movements, where a rolling bearing would be marked. They are not for continuous rotation at high speed. And not all materials are lubricated the same way: some run dry and others need initial grease or relubrication, so it is advisable to keep the one from the original design.

Send us the complete designation and the quantity. Without a code, measure the shaft diameter, the housing diameter and the length of the bushing, and state whether it has a flange. Tell us the type of movement, the approximate load, whether the point is greased and its temperature. A photo of the removed bushing shows the material of the inner layer.