Aluminum Stop Collar Set Drill Bit Depth Stop Superior Split Ring Design - 8 Piece Set (1/2", 7/16”, 3/8”, 5/16”, ¼”, 7/32”, 3/16”, 1/8”) Drill Bit Holder

These drill stops stay in place when you tighten them down. Much better than some othre name brands

When drilling they work great for depth control came with the Allen wrench and a plastic clear case so they don't get lost in your toolbox.

The hole size should have been smaller. Had to wrap aluminum foil to make it fit.

These stop collars did not tighten around the drill bits even when I had crank the set screw as far as it will go. I had to wrap the the collars in painters tape and close the split gaps in my vice. It took a little time to make the adjustments because I had to test fit each collar after making the adjustment on my drill bits. If I closed the split gap too much I used a slot screwdriver to open up the split gap. The collars seem to tighten properly, only time will tell how well they perform.

They do tighten up but you really have to crank on them. I'm sure there are better out there.

I have used these with several different brands, types, and sizes of bits so far and they have worked out well for most. There have been a couple times where the fit needed extra tightening but overall I've been happy with the purchase.

At first I thought that fitting each stop to a specific drill bit would be a hassle. Everyone that uses drill bits knows that we start eyeballing when the marking wear off the bit.That wasn't much of an issue but the fact that these stops don't come in some kind of usable case (not advertised or promised) would've been helpful.The product pics looked good and they arrived as advertised. Immediately, I had concerns about the small and possibly weak set screws. The provided allen wrench for the screws is not strong enough.On test after test, I couldn't get the stoppers to actually stop the drill from drilling pass the intended depth as the stops simply slid up the bit. A waste of time and effort. I shoulda known better and followed my original instincts.

I needed a shallow hole in 3/4 plywood for threaded inserts. A bit finicky but that is more due to the twist of the bit I believe. Worked as expected, tough not burning the ply face. There are Teflon faced stop out there but didn’t want to spend the extra money for them on 6 holes. So good value for the money and superior to the set screw style which I already had.