my analysis of this product showed that its simply not worth the money. The bits get dull after just one use and can't handle heavy-duty projects. While they're marketed as "locking" and "cutting", they don't live up to the promises... The only pro is that they might work FOR basic woodworking or DIY projects. The cons outweigh the benefits in this case, and I wouldn't recommend these for anyone in the industrial and scientific cutting tools market..