I recently purchased a bi-metal hole saw and was delighted with the results. As an industrial and scientific worker, I need to rely on tools that can withstand heavy workloads, and this hole saw did not disappoint. As a result of using this product, I found that it cut through any surface with ease and precision. The one downside was that it was a bit expensive. However, the quality of this hole saw more than justifies the price. Highly recommended!