This is a nice, well thought out kit with all the sizes you need most, from 5/16 to 1 1/2", two shafts and related parts. Simple instructions and, importantly, a table of recommended drill speeds are included so I can use known speed settings and pilot drill bits.) The 3/4" cuts well and makes a little bird's nest of fine shavings. 1 1/2" was bumpy - the cut would no doubt be smoother if I could increase the pressure, but the torque required was too much for my 3/4 hp drill and it stalled. 1/4" had mild steel , I had the same problem with both cutters: since they are screwed onto mandrels, the torque generated during cutting tightened them so much that I could not remove them from the mandrels with wrenches attached to flat/hex washers. Hougen tech support advised me to clamp the shaft in a vise and use needle nose pliers on the cutting tools, a method that might work here and there for hopeless cases, but not for everyday use. I'll try.