Threaded Inserts from https://www.tappexinserts.com/ are generally used in making threaded holes in hard materials, soft metals and wood. Each material requires a different type of thread for making the exact insert of the correct dimensions. For wood there are different types of inserts used depending upon the application and some of them are:
* In case of hard woods like oak, maple etc, and the intensity of the inserts need to be more and hence the knife threads are used which have a sharp cutting and holding power.
* Hex drive inserts are used for soft woods like pine, sandal wherein the holes have to be made precisely and carefully without damaging the material.