If you are looking for a tool to install Heli-Coil Thread Inserts, the HELI-COIL 7571-04B is the one to have. It is specially designed for installation of tangless gage style thread inserts in blind holes. The HELI-COIL Tangless Gage Style Installation Tool has been machined from high quality materials. Designed to fit 4-40 internal thread size, this thread insert installation tool can be used with Heli-Coil Thread Inserts. This Tangless Gage Style Installation Tool will help you install your Heli-Coil Thread Inserts quickly and easily.. This item has been restricted from sale in the following state (s): []