Helicoil Metric Coarse Thread Repair Kit includes inserts, complete instructions, Heli-Coil tap and installation tool. It is made from high quality material and is extremely long lasting. This metric coarse thread repair kit is used for repairing tapped holes which have been stripped or damaged, due to wear, corrosion and over torque. The plug style tap is 3/8 – 16 that requires a ¼ hole drilled. The specs for the HEL570-6 tap is major diameter of 7.42 mm (outside thread diameter) with a 1 pitch (1 thread per mm).