Can you drill a hole through an AR500 steel target?
October 27, 2017
As you are probably aware AR500 steel is some tough stuff. Normally we laser cut everything but for this project I needed an extra hole for a prototype and I figured it would be a great time to test out something that I had heard… You can drill through AR500 steel with a drill press and a carbide tipped masonry bit.
My background is in Engineering and I’ve been involved in projects before where we needed to make a slight modification to a hardened piece of tooling. So hard in fact that it makes AR500 seem comparatively soft. What did we use? That’s right, carbide bits and/or end mills. Even with the right tooling and a full-size Bridgeport mill, it’s still a difficult process that’s prone to tooling breakage so I was a bit skeptical as to how well this would work. We’re talking a cheap, carbide tipped masonry bit instead of expensive carbide tooling and a cheap JET drill press instead of a tough as nails Bridgeport mill!
Fortunately, it went quite well! Some observations I made are…
The masonry bit tips aren’t very sharp. Even on the drill press it tended to “walk” on me at first. Take this into consideration and perhaps try to use a center punch to help prevent this. I did not but it wasn’t the end of the world for my application.
My drill press is not very heavy duty and the table was certainly flexing under the force I was putting on it. The force was necessary because if you don’t apply enough force you’ll just generate heat instead of cutting material and you’ll ruin the bit before you’re through your AR500. You'll have to find the right balance with your equipment.
I used some cutting fluid/coolant to help things along. Typically, these are used to increase the longevity of your bit but for the few dollars the bit I used cost I wouldn’t sweat it too much if you just need a hole or two. If you’ve got some coolant handy though, you might as well use it.
In the end, the process worked reasonably well and was certainly worth the few bucks it cost me. If I ever need the odd hole or two in the future I wouldn’t hesitate to use this method again. Any more than that and it’s back on the laser for me! Check out the video I made to show you the process.