ZELCAN 10 Sizes Titanium Step Drill Bit, 1/4 to 1-3/8 Inches High Speed Steel Drill Cone Bits for Sheet Metal Hole Drilling Cutting, HSS Multi Size Hole Stepped Up Unibit for DIY Lovers Electrician

I just started drilling holes in plastic. I originally bought some smaller step hole drill bits in a kit. But they weren't big enough for anything I wanted to drill. That was my mistake, I didn't actually look up or measure the sizes of the connectors I had, I just went by how big I thought they looked. So, I ended up buying this 1/4 to 1 3/8 inch bit. So far it has been working out pretty well. Just keep steady pressure while drilling and it will slowly strip away plastic until you get to the desired sized step. I am an Amazon associate and may be compensated for any purchases made after clicking any link I provide.

high quality

A valuable lesson learned is that drilling through sheet metal with a 12V drill is inappropriate regardless of the bit used. Despite that, I got the majority of the way through before my drill motor burnt out. 18V did the trick.Knocked off a star because it came pretty full and caused difficulty in creating a smooth opening without additional filing. I'm not a handy person and I don't know how one would go about fixing that, so take this comment with a grain of salt.Additionally, having the measurements etched on the side is great as you can mark the level you wish to drill to and see it clearly the whole way.

Good

Worked perfectly with the hole size I needed !

works great

This bit allowed me to neatly enlarge a 3/4" diameter hole to 1-1/8". It goes up a little larger than that to a max of 1-3/8". I was drilling on only about 1/8" sheet metal, but even that thin the back side of the hole was slightly smaller due to the conical shape of the bit. This didn't affect my project at all but if the metal was much thicker, I would've needed to have access from the back side also to even out the hole diameter. Overall though I wish I'd bought one of these a long time ago and it's well-worth the coin to me just for the first project.

I had one project, a simple project, drilling a 1 1/4" hole in the side of my smoker, thin metal smoker and this thing couldn't even do that. It was working great right until I got to the size just under the 1 1/4" (go figure), then it wouldn't go any further. I request a replacement, hoping it was just a fluke....new one came in and same thing, even though most of the hole was drilled out, it wouldn't go up to the 1 1/4" size.