Heli-Coil STI (Screw Thread Insert) taps are used for general and machine operations. The standard STI tap can be used as a basic tool to create threads ideal for threaded inserts. It is recommended that these taps are used with a CNC machine or other high-precision equipment in order to ensure a proper class of fit.
Heli-Coil offers STI taps in four styles:
Accuracy of the finished thread when the insert is installed is dependent upon the accuracy of the tapped hole. If the finished tapped hole gages satisfactorily, the installed insert will be within the thread tolerance.