The inner outer reamer set offered by Orix has a European-patented design for repairing and fastening damaged bolts. Made of durable material, the set is effective on steel, wood, fibreglass and hard plastic. The external chamfer tool works on round stock or threaded rod, while the inner chamfer tool is used for steel pipe, aluminium tube, etc. Lubrication oil will improve the set's performance. It includes every function the user will need to work with, states the manufacturer. www.orix.imb2b.com