I hesitated before purchasing this set due to the low star rating and some bad reviews. However, I bought this kit for hydroponics and therefore drilled plastic and not wood or metal. I can tell you this hole saw kit is a fantastic investment and value for money if you are not drilling into tough materials. However, I definitely see a lot of people complaining about the quality of drilling in harder materials as personally I definitely wouldn't trust wood and metal. In general, it just depends on what you're going to use it for, but set your expectations accordingly based on what you're going to use it for. Although I will mention that even when drilling through plastic the saw will sometimes try to fall apart (never enough to get into an accident but it does get a little loose) so that might be a different matter but keep that in mind should keep. Again, think about the price of the item, you can't expect great quality.