This part of ISO 3547 specifies the test data for outside and inside diameters of wrapped bushes made of solid and multi-layer bearing material for plain bearing applications. It also specifies test designations. Since the wall thickness of the bush is measured in the free condition, no special test data is required for this on the drawing (see ISO 3547-5 and ISO 3547-6). NOTE Depending on the manufacturing method, the back of the bushes can show isolated light depressions and, similarly, bushes with lubrication holes, grooves and bore indentations can show distortion. The wall thickness must therefore be measured away from these areas