Century Drill & Tool 73512 Adjustable Drill Bit Depth Stop, Two Sizes of Drill Stop Collars Included, Drill Stop Fits All Drill Bit Styles, Durable Delrin Plastic for Metal, Masonry, Formica, & Wood

These are cool and work well. Really easy to install and you don’t need any tools for having to tighten a set screw. Good buy. I recommend

The larger of the two stops works flawlessly. Drill bit inserts and tightens down easily and does not move on the bit once installed. The plastic face is a real benefit since it only contacts the area immediately adjacent to the hole, whereas steel stops tend to burnish the wood surface if you allow the stop to contact the wood. The jaws on the smaller of the two units do not open up enough to allow anything other than a 1/54" bit to pass through without dis-assembly and reassembly, which renders it basically useless. However, I have made frequent use of the larger stop, and it works well enough that I feel it justifies the total price.

Drill bit stop was ordered to put 8 shelf bracket holes 1/4" into inside sides of a 1/2" thick furniture cabinet. Stops were easy to install on bits, worked PERFECTLY every time without needing any adjustment for slippage. Depth stayed true. At completion, I removed and took apart the stop to see if bit had cut into plastic and was amazed that the stops showed no wear whatsoever. That means when the front of the stop reached full bit cutting depth, the inside of the stop held tight against the drill bit. Also, the surface around the finished cut holes showed absolutely no marks of any kind from the stop. You get a stop for larger size bits, and a smaller stop for narrower bits. This is a super product I will use again, it's very affordable, and it's made in the USA!!!! How much better can it get?

Mostly worked as intended. Sometime it would slip down the drill bit but I don’t think I can blame the product for that. I was likely pushing to hard.

There are two depth stops and the small one seems unusable. I nearly broke it trying to get a small bit into it. Stressed the plastic until I saw it getting white and about to come apart. Frustrating. Maybe there’s a secret to inserting a small bit? *** After several efforts to use these, I've decided they're pretty useless. Good idea, poorly executed.

The collars seem to work OK and I wouldn't discourage anyone from purchasing them. There's just the two of them but I still find myself fumbling around some with the different sized bits trying to figure out which collar should be used. And I find that the reason for that is that I want to use the smaller one if possible ... reason being is that both collars are fairly long (The larger one is approximately 1.75 inches long, the smaller about 1-1/8 inch long). And usable bit length once in the drill as compared to collar length can be an issue with what's left to drill with. The collar length can leave you with not all that much of exposed bit to drill with (even with my explanation once you try it you might end up being a bit surprised by the limitation). The picture that shows the collars on bits ... those are fairly long drill bits ... very possibly longer than the one's you may have. However if you have long bits then that may not pose a problem for you. However. I found it posing a problem for me more often than I would have thought. Anyway, just FYI. One good thing though: Most stop collar sets are metal with screws. And I've yet to find one that didn't disappoint me one way or another. The good thing about this set is that they won't damage your bits. That I definitely like. In that way they're unique based on my experience.

I think I have four sets of metal drill stops. The split ring with tightening screw on the side, and the solid ring type with center pointed set screw. None of them set perpendicular to the drill bit, and they often come loose. I kept buying sets hoping to find a set that worked well. Enter the Century drill and Tool drill stops. Way simpler and works like it's supposed to. They grip the bit in a fashion similar to a drill chuck, only with four "teeth". Well worth the money. And it does cover, "Adjustable drill stop set fits 1/16-Inch to 1/2-Inch diameter drill bits". When I originally tried to order these, they were shipped by a business other than Amazon, and the shipping doubled the price. Now that Amazon ships them, shipping is free.

These are very handy. I have three sets. I did notice that the large one slipped on the drill bit when I had been drilling a lot of dowel holes, but I didn't tighten it as firmly as I should have. The good part is they don't mar the wood surface, are better than a block of wood, especially in tight places. But keep them tight. If you are doing production work, drilling lots and lots of holes, you might want a metal stop, but even in that instance, these should work well. My only concern, hence four instead of 5 stars, was how much I could tighten the stop without breaking it. It seems very sturdy, though. And the price is excellent. I bought more than one set because when doweling, you need to readjust the stop when going to a thinner piece of wood. By having two, you can have the longer setting for the edge dowels, and the shorter setting on a second drill bit for the surface dowels. That said, these are very easy to set and don't require any tools, so you don't need to search for a small screwdriver or Allen wrench. I recommend it.