All HeliCoil Thread Repair Kits including the Professional Thread Repair Kits are used for creating stronger internal threads in all metals, composites, polymers and other materials by repairing damaged or stripped internal threads and regaining the original thread size. HeliCoil Thread Repair Kit creates longer lasting durable threads, avoids thread over-sizing, increases the possibility of higher torque application in weaker metals, significantly reduces the bolt breaking problems & HeliCoil being made of stainless steel protects against atmospheric corrosion. HeliCoil Professional Thread Repair Kits include everything required to do the job right – good number of inserts each of 3 lengths (short, medium & long) for multiple applications, HSS drill bit ,Finishing tap, installation tool and tang breaking tool – all in a rugged new box. These kits are available in metric range from M2 to M12 and in UNC/UNF range "4-40 to 1/2”.