This is my first set of end mills that I have bought. I bought this for a number of reasons, firstly to make a t-nut and to have several end mills on hand. The material chosen was 12L14, which was considered an easy-to-machine material. I chose very conservative cuts and advanced them by hand to extend the life of the cutter. After about my 8th pass, the 1/2 end mill broke the edge and cut off part of the groove on the same edge by about 1/16 inch. I didn't expect this to happen. I realize they are inexpensive for what you get, but with careful use I would expect them to last at least a very small project. I ended up replacing the 1/2 end mill with a carbide end mill. Equivalent to; and ended up paying twice as much for an end mill as for the whole set. No offers. You get exactly what you pay for.