We had a similar problem like this with 1 1/2" carbide drill bits, we never had any problems until one of the "bosses" decided to save some money and buy some cheaper bits. They some times would break after the 4th or 5th use so I did some research and found out that they were not the USA made ones we used to get they were made in China, fact is that China does not do well in making any kind of tooling so I would check and see where they came from |