These can be used as a replacement for the used insert in my Anytime Tools 5 pcs. 3/8" mini lathe with interchangeable carbide inserts. They fit all of my mini lathe bit sets that use triangular inserts. They will last longer than the original inserts when used when turning T-6 aluminum. I have not used them for any other type of material. I will order more when I need new inserts.