... , sliding block, ball socket and so on, SF-2 can take full advantage of less grease to ... boundary lubrication condition, But under oil-free condition ,SF-2 the frictional behaviou and permissible PV value ... so on should be applied when being installed. SF-2 material follows special wearing rule as shown ... . It is approximately five times long. When SF-2 bush is installed with application of grease ...