Why does every size of key-locking insert require a different drill and special tap size?
A7. Because of the need to limit the wall thickness of the insert to reduce the loss of strength that occurs if heavy wall inserts with standard V style threads are used. Only Full-Torque thread repair inserts uses the same drill and tap for several different internal size threads. Only 15 different tap sizes are used for all sizes ranging from or 6mm up to 2-3/8 or 60mm internal threads.
