Helically wound coils made out of diamondshaped high tensile 18-8 stainless steel wire. These inserts, when installed inside a tapped hole, produce permanent precision internal threads, conforming to standard specifications, and in the process protect the parent thread from damage against shock, vibration, corrosion, stripping, etc. These are specially suited for use in soft material like aluminium, cast iron-and others where often the threads wear out fast. The insert, in the form of coil, aligns itself with the parent thread, eliminating lead and angle error, if any. Hence, when the bolt is assembled through the fitted insert, the load is distributed uniformly all over the thread, thereby increasing the life of the thread to an enormous extent. The process of installation involves tapping with special fastman taps, driving the insert with an inserting tool, and breaking the tang from a v-notch provided at the bottom of the insert, using a tang break-off tool. These inserts are available in a wide range of sizes from 1.6 to 39 mm or equivalent in inch series.
