zz10w self-iubricating guide bush din 1)material : suj2 2)hardness : hrc58~62 3)custom sizes available by request. 4) various bushing makes were field tested on the same lift mechanism within a progressive die. operato did not lubricate the bushings. 5)with regular lubrication maintenance, life of bushing is significantly increased. 6)bushings are ideal for high production environments where operato do not lubricate the bushings at regular intervals or where lubricant contamination, debris or byproducts are undesirable.