Tapered sockets are made for quick assembly and disassembly of pulleys and other transmission gear without having the want for specific tools other than a hex key. Various machined holes guarantee instant local community, staying away from pricey manufacturing unit downtime. Bushings are keyways machined to British Regular Specs. This is in addition to the clamping screw, which is sufficient for the essential torque in many instances. Tightening with a tapered bushing gets rid of any gap among the hub and the bore, which removes fretting corrosion.