Based on my observations these industrial drill bits did not perform well in my manufacturing facility. The quality of the product was subpar and resulted in a lot of broken drill bits. The packaging was also lacking, causing some of the bits to arrive damaged upon arrival .On the plus side, the price was relatively inexpensive compared to other industrial drill bits on the market. However, in this case, you DEFINITELY get what you pay for. As a professional in the Industrial and Scientific field, I cannot recommend this product..