As a new buyer, I was extremely disappointed with this Industrial and Scientific product. As a result of my tests, I determined that the drill bit is extremely dull and defective. It has made drilling into even the softest materials a task that is impossible to accomplish in a timely manner. The only positive aspect of this drill bit is its length. The biggest con is that it does not live up to its own specification. I wouldn't recommend this product to anyone in the industry.