The M6 insert requires an 8.5mm or 9mm pilot hole; the optimum diameter is dependent on the hardness of the material you are using. These inserts are often used to replace existing threaded holes that have been stripped or are otherwise no longer suitable for securely holding threaded fasteners. Compared with self-tapping screws, screws and bolts with threaded inserts can handle higher axial and radial loads. A threaded insert, also known as a threaded bushing, is a fastener element that is inserted into an object to add a threaded hole.
