Metric Thread Repair Kits. Internally stripped threads? Look no further. These thread repair kits are designed to repair stripped threads in a variety of metals such as aluminum, aluminum alloys, steel, and iron. The threaded inserts included in these repair kits once inserted become a fully functional thread with a strength exceeding the original. Following the detailed instructions included in each kit, even the most novice do-it-yourselfer can repair stripped threads permanently. Each kit includes the proper tap size, threaded inserts, and insert setting tool.