Drilling & Countersinking AR500 Plate Steel. This Is Some Tough Stuff!!!

***RUNOUT***. The runout you are seeing is the "Magic Chuck". It's a quick change tool holder. It allows tool change without stopping the spindle. They are great for a lot of things, just not carbide. Lol. My mistake and lesson learned.

You know it is a big job when you're sitting on top of the work while drilling or machining it. Haha!

We've drilled many holes in AR plates. We used a carbide hole hog bit. Then a counter sink bit. Using a mag drill. The hole hog bit only cut the periphery and left a plug. The cheek plates in most of our crushers were 3/4 thick and used 3/4 counter sink bolts. Good luck.

Allied spade drills are the most profitable thing I've bought for my shop. Far better split point and geometry than you can get with hand grinding drills, thru coolant, coated, and they'll out last a twist drill 10:1.

I drilled a lot of holes in AR500 plate with a mag drill and Slugger annular cutters. I've drilled holes in forklift forks with them. Countersinks were more of a problem. We found AR plate hardness to be too inconsistent so we switched to Astralloy EB450 plate. We had to torch holes and weld the plates down but they lasted 4 to 5 times as long as AR500.

A while ago i had to drill a lot of 3/8 holes in HRC61 material. My supplier provided me with a pair of carbide drills. His instructions were. Max out the speed on the drill press.(1200 rpm) Keep a constant feed rate,no manual feed.And certainly no coolant at all. The carbide went through the material like butter. I returned the second drill because i didn't need it.

Used to drill a lot of AR500 plates for a mill. We didn't use any slugger bits, but we did try carbide on our 4ft carlton. The same thing happened when we tried the carbide bit. Snapped the bit on the first cut. Had luck with cobalt bits. You had to keep constant pressure on the bit. If you let the bit ride in the cut just for a second it would get hard fast and take the edge off. We did maybe 400 to 500 pcs at a time. A couple of holes my guys had trouble with, I heated with a torch and ran the cobalt bit thru hot. Had to keep the edge sharp. Yes they were a pain in the keyster.

That wobby in your drillchuck surely made fast work out of your carbide drillbit.. Carbide drills like rigidity, they absolutely hate extra side pressure. I am almost certain it wouldn't have broken if it was actually running somewhat true.. edit Ah i see you even mentioned it would have worked with more rigidity on the boring mill, 100% agree

I used to make oilfield bitbreaker plates (they locked the drill bit so the tongs could screw or unscrew the the pipe from them) out of AR500 and A514. These plates were about 14x14 and had a horseshoe shaped notch in the middle about 7" wide for the bit to go in. We drilled the handle and lock bar holes with Iscar Chamdrills with thru coolant and did the machining with Mitsubishi feed mills for roughing and MA Ford 6 flute solid carbide endmills. We ran full flood coolant along with airblast to evacuate the chips. Stuff actually cut nice and would only kill the tools when you could not evacuate the chips fast enough. Nice work you are doing there.

Josh, Love your Channel. I have drilled Thousands of Holes in AR 500 Plate. This was our procedure. Using a Radial Drill or Mag Drill we ALWAYS first ground off the Mill Scale. This increased the life of the Cutter. We would always use a Cobalt Annular Cutter and a VERY GOOD Cutting OIl, Coolant never worked that well. The more we flooded it with the Oil the better it did. TURNING SLOW. Then used a Cobalt Countersink flooded with Oil. Not trying to Criticize but this worked for us and drilled thousands of holes

I have a tungsten tipped three-quarter inch annular cutter which I used to drill holes in a cutting edge for a excavator bucket. It was $200 20 years ago. Worked a treat. I still have it

Great job. Kinda funny to watch you using a carpenter's tape measure and a drywall square to lay it out... when pretty much everything else you do has to be so precise. 😁😆

I always hand thin the web so there's as little rubbing in the center as possible. Reduces the feed pressure a lot. More harder the material, more shallow back rake helps too. Also, I NEVER use center drills but use Spotting drills for a starter, which are much more rugged and don't shatter the point. Center drills break unpredictably it seems. I only use them for center holes on the lathes.

Thank you Josh!

Love your content. Congrats on how much your channel has grown.

So I know a guy that moved from Australia to Thailand, he works at a place that builds armoured cars. What he would've done for this is sharpen a concrete drill on a diamond or CBN wheel. You can make the tip so it can cut into the steel.

I love my cobalt drills! Way to go.

I cut AR500 before. It's safe to say that carbide doesn't last on this stuff. I haven't tried the hanita coated carbide endmills on it, but I can't imagine that they would last significantly longer.

wonderful Josh.......cheers from Rainy Florida, Paul

Hell ya Josh. This video was extremely helpful