As described

I have a number of inexpensive countersink bits that always seem to hide themselves when needed. Usually they chatter and/or burn the workpiece anyway so its not a big deal if they languish in a dark drawer somewhere. When I saw these cobalt countersink bits I decided to give them a try since I haven't been too impressed by the standard HSS type. These are priced a bit higher than a HSS bit at the local store so I was expecting better performance. This 5/8" bit arrived in a handy plastic sleeve, covered in sticky anti-rust oil and generally looking good. After a quick degrease I tried it out on some alder plywood just for kicks. It did respectably, leaving only a small amount of fuzz around the edges. Next I ran it into some C1144 semi-hard steel which it handled with ease. Finally I tried it out on a hardened steel bolt that I drilled a hole in, and once again the countersink took it like a champ. I noticed a very small amount of chatter when easing off the cutting pressure, so I tried again. This time I quickly let off the cutting pressure and withdrew the tool. Zero chatter. All of the cuts were smooth and consistent with the exception of the slight chatter already noted. I couldn't see any damage or wear to the cutting edges after my several test cuts so I feel confident this will last me quite a while. Countersinks generally have sharp, delicate edges so be careful not to get them hot. Run them fairly slow and use cutting oil to get maximum life from them. Overall I'm quite happy with this cobalt countersink. It definitely outperforms the HSS bits I'm used to.

I keep a countersink handy in my toolbox and use it pretty often to sink screw heads flush in the material. It's usually wood, but sometimes in metal. Up until now I've kept a sawn off boring bit in 3/8 diameter and it has served me well, but it has now retired. This bit is better because it is more convenient; being a hex shaft I can pull make my countersink, change it out for a screwdriver bit and keep going. That saves me time. I like that it has five flutes instead of two, that cuts cleaner and the surface won't chip out. I like that it is made of a more durable metal, so it's going to stay sharp a really long time. I also like that it is shorter and is a bit easier to store. I will probably keep it in the plastic sleeve it came in, to protect it from getting nicked by other tools, and to keep it pristine (hah! like anything in my toolbox that gets used is pristine!). I like that I can use this for both wood and metal. The 3/8 inch size is perfect for the majority of screws. I didn't realize how much I was going to like a new countersink bit until I got this one. Very happy with it.

I have a workshop that is at a different location than my house, but between making cabinets at my workshop and doing projects around the house, my countersink bit is always at the wrong location, so I figured I would get a second countersink bit so that I don't have to always bring the one that I have back and forth. I mostly work with wood with a little bit of metal occasionally. So far, I've only used this with wood, but it countersinks nicely with little chatter or fuss. I like that it has a 1/4" hex shank (my other one is a round shank) with the ball detent for an impact driver--more options make for faster work when I can keep a drill bit chucked in my drill and this countersink in my impact driver instead of switching back and forth. Obviously I wouldn't expect any significant wear on the bit from using it in wood; once I have a chance to try this on metal I'll report back.

I use countersink bits all the time for reaming holes that I drill through in metal for things like mounting casters. By using it on both sides, you clean the hole really well, as long as too much pressure isn't used. Of course, using it on metal as opposed to plastic, PVC or wood, you need some durable and hard metal, and this fits that by being made from cobalt steel. The aluminum nitride coating increases surface hardness to 91 which is really hard for a bit. It has a hex shank so there's no slippage while drilling, and it came in a square slide together case to protect it. I'm very happy with this, and would get again.

This 5-piece countersink drill bit set contains the following sizes: 1/4", 5/16", 3/8", 1/2", 5/8", and 3/4" The choice of cobalt high-speed steel drill bit material with the titanium aluminum nitride coating means that these drill bits will hold up to a fair amount of abuse. This coating will extend the life and the possible machining speeds of these drill bits may be used for beyond that of standard non-titanium coated drill bits. The shank has a hex design that will keep these step bits from spinning in your drill's chuck and they will work on 1/4" quick connect arbors. I don't recommend using these countersink bits in an impact gun. The 5 flute design helps these drill bits cut faster, run cooler, and clears out more chips while you are drilling. The included storage case will protect these bits when not in use and it won't take up an excessive amount of tool box drawer storage space. This countersink drill bit set is not inexpensive by any means, but most of the time you get what you pay for. I recommend this TOOLANT 5-piece countersink drill bit set.

I find the Titanium Aluminum Nitride Coating (TiAlN) to be the most interesting feature of this Toolant Countersink Drill set. Here's what I learned recently about the TiAlN coating. This information comes from someone who has more expertise than I do. (He's a journeyman tool and die maker.) The TiALN coating is an all around coating that will work well on anything from wood and plastic to hardened steel and even super alloys like Inconel. The TiALN coating is also one of the better coatings for milling or drilling without coolant so, if you have a home shop and don't like to bother with the hassles of disposing gallons of old coolant, tooling with the TiALN coating would be a real good choice. I'm a little confused by the term "Noir-Ti " in the product title. But it also clearly says "Titanium Aluminum Nitride Coated." The bullet points also expand on that: - Titanium Aluminum Nitride Coating - Increases surface hardness to 94HRC with outstanding heat-resistance, so your drill bit cuts fast and stay sharp. Those are exactly the advantages TiAlN is famous for, and that's the primary reason I ordered these and their main advantage IMO. They come in a nice case, the set has a good size range, and the hex shanks are interesting. I would buy a second set of these if Toolant introduces a TiAlN coated set with a 60-degree angle. These are 82-degrees.

These are nice countersink bits that drill a smooth hole with crisp clean edges. The coating seems to work far better than I expected since even after drilling 6 holes with one of the bits, I don't see any noticeable wear. These are quickly taking the place of other bits I have and am really satisfied with them.

Broke two of these countersinking mild steel. Save your money for better products!

These countersink bits seem very nice. I just hope they last. I mostly use these on wood, so I should be fine. Not sure how long they would last if used on metal. I like that they offer a 90 day money back guarantee!