M35 Step Drill Bit for Metal, 3/16 to 7/8, Cobalt Bits, Extra-Heavy Duty for Stainless Steel, Hard Steel, Mild Metal, Aluminum, Wood, Industrial Grade, 12-Steps. Co35A2

This allows you to cut holes WAY faster then other step drill bits. This lasts thru many drilling which a lot may break after just a few drilling. It's a must have if you work with drilling a lot because it will drill and drill and still look amazing and work like it's brand new. It's easy to clean and use again and again.

Me agrado lo rapido que corta el asero

I used it for installing electrical panel and boxesWonderful tool

Don't know how i did which out one

The shaft broke under normal stress before I could really get my money out of this bit

Only drilled a few holes with this. Fast & easy. I cannot say whether this will last many more uses. For occasional drilling, I would highly recommend buying this step drill bigs, instead of several bits of different fixed sizes.

I've been building out my camper van using 8020 and 3030 extruded aluminum. To attach it to the walls of the van I need to set a rivet in the support beams then mount this to the rivet with a bolt. I have to drill a hole in the 8020 for the bolt and it's important to get the head of the bolt flush with the track in the 8020 so it doesn't obstruct any attachments I need to add. This drill bit is the recommended way to go. I was a little nervous to try it, but I followed the instructions I found on youtube and it worked great. This bit seems to hold up well and I should be able to get all the holes cut without having to replace it.

This is one heck of a hole ripper. I have been using an older HFT bit that didn't have the spiral design. The cobalt construction makes this way tougher than the coated style bits. Just remember to use a quality cutting fluid when drilling any metal.