【working principle】This thread repair set can be place in the screw hole of the workpiece such as aluminum to form a standard internal thread with high strength,wear resistance and high precisions. 【stainless steel】Thread inserts produced of high-strength -shaped steel wire with high strength and wear resistance. 【120pcs in different size】This thread insert set contains 60pcs inserts from 3mm to 12mm which can meet your different needs. 【wide applications】This thread repair set can be widely used for high voltages switches gear,microwave communication,automotive parts,aerospaces precisions parts,electronic products,air equipment,radiators. Suitable for enthusiasts,professional handymen,and mechanics who demand reliability and strength in their fastening.