Occasionally, you may experience stripping of the internal threads of a nut or bolt hole, usually when the torque is exceeded. Thread stripping occurs very often, especially when working with aluminum elements, as aluminum is so soft that it is very easy to damage the thread.
As a rule, only partial shearing of the external or internal thread occurs. After calibrating the thread with a tap or lerkoy, the thread can continue to work. However, sometimes the thread is damaged to a large extent. When this happens, there are three options:
1) Ream the hole and cut the thread with a diameter according to the next larger size and use the larger diameter bolt, screw or stud accordingly.
2) Drill a hole and cut a thread in the hole to install a screw plug, in which follow it to drill a hole of the appropriate diameter and cut the thread according to the original size. It is also possible to buy a threaded insert pre-threaded in the respective (original) size. In this case, simply drill a hole of the prescribed size and then screw the threaded insert into the hole using a process bolt and locknut. After the threaded sleeve is fully seated, the bolt must be unscrewed together with the lock nut.
3) The third method involves using a proprietary thread repair kit such as Heli-Coil or SHmsert. These easy-to-use kits are designed to repair damaged threads in through and blind holes. Both kits cover a wide range of thread sizes and types. Drill a hole, cut the thread with the special supplied tap, screw in the threaded insert, and the threaded hole will match the original diameter and thread pitch. Regardless of the technique you use, work calmly and carefully. Any kind of impatience or carelessness when performing any of these relatively simple procedures can negate the results of a day's work and lead to additional large costs if you damage an expensive item.