4PCS Cobalt Single-End Countersink Chamfer Tool Set - Heavy-Duty M35 90-Degree Countersink Bits for Metal, Stainless Steel, Copper, Wood, Fiberboard,SAE 1/4"-3/4", 2-5, 5-10, 10-15, 15-20MM

Work great

I love this bit; working on wood, metal, and plastic. Nice clean cutting; makes project assembly look proffessional.

I used the smaller of the three (not sure when i will ever use the larger two, wish i could have purchased a smaller set of three for household uses) and drilled a pilot/through hole for the h/w i was going to use. Using a hand drill with adjustable collet, the chamfer tool worked perfectly. i needed to increase the screw diameter size, hence the chamfer diameter needed to increase slightly and i was able to resize w/o any difficulty. All told, the tool cuts nicely w/o chatter or wander and gave me the countersink i needed.

I was unsure how good these would be compared to other brands I bought. But decided to give them a try. When used with a drill press, they perform well when the piece being countersunk is clamped down. If using with a cordless drill however, it is a bit more difficult to get a symmetrical countersink. I’ve used them to countersink 3/8” plate steel for 5/16” bolts and they performed better than expected. I also use them to debur and they work well.

Amazing tool great for fine woodworking and way better than the conventional counted sink bit we are all familiar with, all my other woodworking friends are also impressed. A+

I don't usually write reviews but I just had to for these bits. I don't always need the highest quality tools for my work but I had a project that required a lot of work on 316 stainless and needed some high quality taper bits. I had gone through several at that point but I gave these a shot thinking I would likely be disappointed but wow I was not. These are very hard and cut cleanly through the 316 with ease. Not only that but they lasted through the entire project. I want to buy a second set in case they go away but with how well these are lasting not sure I need to. So I thought I could do the next best thing and write a review so hopefully they can keep sales up so they continue to sell these. These are super high quality tools from Amazon so please give them a shot before you end up with the junk that wont last a single cut. This set comes in 3 sizes so it's basically a one time purchase that will last in your tool set for many years under normal use.

Finally used this today. Great reaming bits for the price. Cuts smooth and steady. No chatter like other 4 blade cutters. Will recommend.

These are well made