I've been using the self centering bit I bought from Harbor Freight for years and am frustrated with it, the HF one has a very weak spring that doesn't keep pushing the fold back in. Worse, the fold in my cheap bit is very loose and sloppy which often results in the hole being off center.I saw a good video recently with an English guy saying how nice it is to work with a quality club and how annoying it was.I had to a cheap one will work with this. Having only had experience with a HF bat I didn't understand what I was missing. Wow what a difference it makes what these snappy parts do in your experience! They are a lot more expensive than some of the cheap kits available here on revain (about double) and they don't have that many dimensions but they are realistic. In fact, the dimensions you get in this set are all you'll ever need for a cabinet or door hardware. They have very comfortable springs (it's almost impossible to press the folding part with a finger) and are very snug with no wobbling. The drills are all straight and made of decent carbide. After many holes drilled in the last week they are still cutting the same as a few weeks ago. I had no idea how much work my cheap instrument actually cost me. I don't know how good the cheaper kits are here at Revain, but I do know the HF beats suck. While this set is probably twice the price of the others, it's still not a very expensive purchase. I therefore strongly recommend that you spend a few dollars more and get yourself this beautiful set that will accompany you for years. I should have been many years ago.