... lubrication condition, But under oil-free condition ,SF-2 the frictional behaviou and permissible PV value is ... be greatly extended. Therefore the advantage of SF-2 material is that oil shall be added with ... It is approximately five times long. When SF-2 bush is installed with application of grease such as ... condition, for instance, when PV value is about 2.5MPam/s, its service life will be about 200hr ...