M3 x 0.5 Metric HSS-Co Combination Drill and Tap Bit

I used this combo bit to drill and tap a hole in the dropout of an aluminum mountain bike for a disc brake conversion bracket. Once I made the mark of where the center of the hole would be, I center punched it and started off with some cutting oil and a small drill bit for a pilot hole. I then switched to a slightly larger size drill bit to further widen the hole. Finally, using the combo bit in a cordless clutch power drill and some cutting oil, I slowly drilled and tapped the hole. To prevent damage to the threads when reversing out, I un-chucked the bit from the drill and reversed it by hand using a T-handle socket drive. Took some time, but it worked great and it didn't snap. All in all, great product.

Works great with 1/4 hex impact driver, can use with use a drill press or handheld one with a slip clutch, but as the torque will cause a twist with your hand and break the hardened bit if you aren’t careful

I should have read more the product more closely. I would not recommend using these combo drill/taps in steel thicker than 2/4" steel, and use a drill driver with an adjustable clutch on a low setting. I tried drilling/tapping 1/2" steel bar, and broke one when tapping, and one when trying to back out of the tapped & chamfered hole.

I originally bought this to tap and thread some thin steel for a DIY project and they worked beautifully. Since then, I have used the to start tap, simply drill, and even tap into wood with no problem. I would recommend going slow on the drill if trying these in wood as they cut so easily, it is easy to get aggressive and chew up the threads in the substrate. The shank and threads are just as sharp and clean as the first day I got them and I have used over a dozen times. Great and highly recommend

They do fine with 1" or less material. However, if more material you will run out of room. I gave it 5 stars because they do work. Just be aware of their limitations.

For the life of me, I can't understand how this item has such strong reviews. I have attached 2 pics of my experience with this bit set. In the first pic you'll notice that the 5/32 bit is broke. This happened when I opened the package and it fell onto the tile floor. I hadn't even used the item yet, it just fell from about 3 feet, hit the floor and broke. ¯\_(O_o)_/¯. I should have taken this as a sign for what happened next. I got the 5/16 bit hooked up to my drill and attempted to make a hole. It didn't take long for this bit to fail either. As you can see from the pic it broke as well and it maybe made 10 revolutions before it failed. I have bought some junk from Amazon before, but this one is at the top of my list. I'd would venture to say that calling this bit set junk would be a gross understatement. Needless to say, it is getting returned.

These bits are a fantastic idea. The smaller sizes break very easily. The 1/4" broke while taping steel by hand. I drilled the hole with a drill but did not want to break another with the drill whilst tapping. It still broke and got stuck in the steel. Again fantastic idea but need to be built stronger.

I am very happy with this tap set so far. I specifically bought this set in order to get the 2 smallest sizes in the set. Do at your own risk. I saw a video online where a machinist took a small tap and threaded the spring hole on a lower receiver, cut down his rear takedown pin spring to compensate for the allen type set screw length, and he successfully eliminated the need to "smash" the rear takedown pin spring against the stock or sling plate. I have done 2 myself, and I can tell you it has worked great. I put this combination 1/8" - 40 NS drill/tap into a hand "dogbone" ratchet and took my time, making sure to back out the shavings every few 16ths. It came out beautifully. Now I only need to remove the set screw in the event I want to dismantle the rear takedown for some reason, and now I can switch stocks at my leisure without having to worry about losing the spring or smashing/kinking the spring. I also really like not having to hunt for the proper drill size in order to tap. In addition, I also really like having the quick-change ends so these can be used in a hand ratchet, a mini impact, or a cordless drill.