This is a thread repair kit. Low declared hardness and a very large variation in hardness 40-55. But even the upper limit is not enough for the primary cutting. This is not even suitable for garage and country work. For the home, upgrade a rusty bolt or nut. This is the maximum set. I wanted to write how it is, Ombra and such . but, and then I remembered Makita D-37194 (rigging set) and . I absolutely do not recommend