As another user said the bit just screws onto the mandrel and the way it cuts when the bit stops moving the whole blade keeps spinning very quickly due to the heavy weight and dissolves completely. Having a large rotating sheet flying through the air over a project is not ideal. I really need to design it to snap onto the shaft like my other saw set. Unfortunately I had to buy these for a project. It works, but you have to be overly careful when using it. Be sure to wear gloves.