I purchased these drill bits for two reasons: I was tired of the cheap bits getting dull way to easy; and I wanted to buy American. Yesterday I needed to drill a couple of ½ inch holes in a steel frame rail, it was like going through butter with a hot knife. I started with a smaller size and worked my way up and each one cut with ease. I'd recommend them for anyone wanting a good set of bits!

After using these for close to two years, can say they as fantastic. Pretty much unbreakable and have not dulled despite countless hours of drilling through nasty metal, uncluding bolts. This fractional set is a great starter set. Add the metric, letter, and wire/number odds and ends as needed. Expect to have these for life.

If you are a weekend warrior or just getting started and you are kicking yourself because drilling is harder than you imagined or saw in a YouTube video, it's probably not you. It's probably not your drill (assuming you have something halfway decent). It's your drill bits! Most of us at some point will get to the point where we realize the return on investment from quality tools like these outweighs the upfront cost.

I'm not a machinist, just an enthusiastic handyman on a budget. As such I am always looking for free materials for my projects.

Collapsible metal bed frames are commonly discarded and are a good source of free angle stock. Working with them is difficult, however, because they are made of hardened steel. Common drill bits have a hard time penetrating this steel and dull rapidly.

Cobalt bits are recommended, but they are much more expensive than high speed steel bits. I had no experience with cobalt and was reluctant to risk the investment.

I purchased a single bit at my local hardware store to give it a try. What a difference! It went through the hardened steel like butter, so I decided to purchase a complete set.

My local stores and big-box retailers only carried small sets. This set of Chicago Latrobe 550's is far more complete and comes in a good quality metal case. Delivery was rapid. The bits perform perfectly, just as I expected.

I am very pleased with my purchase and I recommend this set.

Best drill bits I have ever owned! Well worth the investment. I can drill through the frame on a Peterbilt with a cordless drill. I was absolutely amazed. The best thing was after drilling 4 holes in that frame, the bits weren't dulled in the least. I have a set of that other popular brand of bits that carry about the same price tag, after doing the same thing with those, the bit is almost shot.

This set is very high quality and can be used to drill hardened items. I am very pleased with this order.