Drilling AR500

[tracyb]

Is it very picky on how thin of metal it will stick to?

very much so. magnetic grab directly related to metal thickness. and that steel max dosn't like to turn on if it doesn't think its grabbing good enough

 

[Steve300xcw]

Thats how my hougen is. Its been a few years, but I dont remember our old milwaukee ever caring.

 

[tracyb]

I like mine so far, drills just as fast as the Hougen. You don't need to be afraid of a breaker tripping and it falling on your face.

i been close to buying it a few times... the other one i would consider is the mag switch drill. pretty limited in bit size tho

Magswitch MagDrill Disruptor 30 - 8100920

Powerful magnetic drill that holds strong to flat and curved surfaces. Easily slide the drill into one position to another. With a safety mechanism built in, the drill will stay in place. Max breakaway is over 1000 lbs.

magswitch.com

 

[WaterH]

what direction are you turning the drill bits?

Are you suppose to turn them?

Anyways, after a few more sharp innings I got the second hole out to 1/2”. To clarify, I annealed the area at the hole and drilled 1/4”, then 3/8” and on to 1/2”. I had to sharpen the bits multiple times. I have 6 to 8 more holes to put in this. Has got to be a better way. I have the good 1/8” bits coming, but now I figure I need good bits for the bigger sizes too.

I also have to put a large hole. (Maybe 2”) I’m wondering if a hole saw will touch it? A plasma would work for that, if mine worked. Maybe one of those end mills with carbide inserts?

 

[Twankie]

What kind of torch did you use to anneal the holes? cut with that

 

[Steve300xcw]

Stepping up in sizes always seemed harder on a bit than just a small pilot, and letting the big one eat

 

[WaterH]

What kind of torch did you use to anneal the holes? cut with that

Oxi-esetalene
Im not trying to cut. I’m trying to drill precision holes.

Edit, if you’re referring to the big hole, yes I can do it with the torch.

 

[Steve300xcw]

This whole thing sounds more like a drill bit sharpening problem

 

[bdkw1]

Cobalt split point, 350rpm, feed hard enough to get chips instead of stringers. I drill shit harder than this every day.

Granted, if it's something production it's getting carbide drills and going way faster, but onesy twosy stuff gets done with HSS or cobalt depending what's on hand.

You want fun, bore and thread a hole in hardened D2.

 

[tracyb]

This whole thing sounds more like a drill bit sharpening problem

work hardening every hole along the way. the best of the best when the finally break down and buy a new bit start off in an already fubar half drilled hole and never learn the lesson.


true story;
i started with a drill doctor and hand sharpening etc. but i used to go thru so many bits doing the same stupid shit that i bought a drill bit cabinet and filled it. (remember i'm a fake it till you make it metal fab guy, i wasn't very good when i started) so i could have at least 10 brand new in every size up to 1/2". all brand new perfect bits. $$$$$. funny thing happened at that very same time, i learned from what i was doing wrong. can see when things are starting to fuck off before its a bigger problem. now drill bits last me so long I can't remember the last time i had to buy new to refill the cabinet.

hand sharpen a bit and think, wow, this drills great.... then notice only one flute is pulling chips... stop. if only one in pulling chips the other is rubbing and work hardening. next thing you know you over heated the bit and now no matter how perfect your sharpening job the bit got soft enough it wont cut. you know shit like that. learning the hard way.

 

[WaterH]

work hardening every hole along the way. the best of the best when the finally break down and buy a new bit start off in an already fubar half drilled hole and never learn the lesson.


true story;
i started with a drill doctor and hand sharpening etc. but i used to go thru so many bits doing the same stupid shit that i bought a drill bit cabinet and filled it. (remember i'm a fake it till you make it metal fab guy, i wasn't very good when i started) so i could have at least 10 brand new in every size up to 1/2". all brand new perfect bits. $$$$$. funny thing happened at that very same time, i learned from what i was doing wrong. can see when things are starting to fuck off before its a bigger problem. now drill bits last me so long I can't remember the last time i had to buy new to refill the cabinet.

hand sharpen a bit and think, wow, this drills great.... then notice only one flute is pulling chips... stop. if only one in pulling chips the other is rubbing and work hardening. next thing you know you over heated the bit and now no matter how perfect your sharpening job the bit got soft enough it wont cut. you know shit like that. learning the hard way.

I can sharpen drills 1/4” and bigger without a problem. I’m very good at matching both flutes. I’ve drilled and taped titanium many times before. That was in a shop where we only had good bits. I think I found a 1/8” bit that was something special because that’s the one that has been going through. But I think I need good bits for some bigger sizes.

 

[Dethmachinefab]

Don't step more than once. Pilot 1/8" and go right to 1/2". Good quality new bit and feed it heavy. Try any coolant?

 

[WaterH]

Don't step more than once. Pilot 1/8" and go right to 1/2". Good quality new bit and feed it heavy. Try any coolant?

I was using good cutting oil. When I drilled the first hole out to 1/2”, I had the plate on a piece of wood and was running water over it from a hose. I don’t have the coolant pump working on my mill. Do you think it’s more important to have the mill set up or the coolant? (I probably have more pressure with the mill)

Edit, Feeding 1/2” heavy with a hand drill is kind of scary. When it gets to the end and try’s to lock up and twist your hand off. Lol.

 

[Dethmachinefab]

I was using good cutting oil. When I drilled the first hole out to 1/2”, I had the plate on a piece of wood and was running water over it from a hose. I don’t have the coolant pump working on my mill. Do you think it’s more important to have the mill set up or the coolant? (I probably have more pressure with the mill)

Edit, Feeding 1/2” heavy with a hand drill is kind of scary. When it gets to the end and try’s to lock up and twist your hand off. Lol.

I'd just use a spray bottle on the mill.

 

[Steve300xcw]

Edit, Feeding 1/2” heavy with a hand drill is kind of scary. When it gets to the end and try’s to lock up and twist your hand off. Lol.

By hand you can feel it just before it breaks through, an ease off the pressure

 

[M92PV4U]

You have to have more horsetorques than the drill.

 

[Eric642]

How fast are you spinning the drill? Try about 250rpm for a 1/2" drill and be sure to keep a good chip load.

 

[Firstram]

i been close to buying it a few times... the other one i would consider is the mag switch drill. pretty limited in bit size tho

Magswitch MagDrill Disruptor 30 - 8100920

Powerful magnetic drill that holds strong to flat and curved surfaces. Easily slide the drill into one position to another. With a safety mechanism built in, the drill will stay in place. Max breakaway is over 1000 lbs.

magswitch.com

That is slick, it's a shame the hole size is so limited! I would love to have a mechanical magnet, my Milwaukee is so old the serial number only has 3 digits and I don't trust it on anything other than horizontal work!

 

[tracyb]

That is slick, it's a shame the hole size is so limited! I would love to have a mechanical magnet, my Milwaukee is so old the serial number only has 3 digits and I don't trust it on anything other than horizontal work!

i'm almost certain that a different mount can be made to do uo to 2" holes. which is all i'll ever need.
when i find time, so probably never.... but i'd like to take apart the steelmax that i have, remove the safety shut off, and make a similar attachment to the mag switch but from commercial door mag locks.

magnets like these;

Amazon.com

 

[WaterH]

By hand you can feel it just before it breaks through, an ease off the pressure

Sometimes you can, sometimes you can’t.

You have to have more horsetorques than the drill.

I just have a Dewalt 1/2” , 20 volt max drill. I have the extra handle on it. I was standing o the steel with one handle behind my leg and both hands pushing. When it broke through, I almost broke the 1/2” bit. That drill has a lot of power when you have it on slow speed.

How fast are you spinning the drill? Try about 250rpm for a 1/2" drill and be sure to keep a good chip load.

Yes, I’m turning it slow on the 1/2” bit. It doesn’t really make much chips ever. When it stops, back to the grinder. You could say I’m a shitty sharpener, but the bit goes through the mild steel like butter. It’s not exactly like this is my first rodeo. I’ve drilled stainless that was a bitch, but nothing like this. I sware I’m getting maybe 20 thou between sharpening.

I’ve had this large drill bit set for years. I got it free when one of my tenants left it in one of my apartments. I don’t know what kind of bits they are. They are gold in color. I’ve always thought it was pretty good quality. I suppose it is just some Chinese junk. The case is nice anyways. It has every size plus number and letter bits.

I guess I’m going to order some good bits in a few bigger sizes. (1/4”, 3/8” and 1/2”) I already have a few bigger bits then 1/2” in good quality that I have ordered for specific jobs.

 

[Eric642]

I heard carbide mason drill also work in AR500 but no experience. A proper carbide drill is really the way to go if you are using the mill or a mag drill but I imagine the mason bits are les brittle with drilling by hand or not quite ideal situations. They are quite a bit cheaper might be worth a try. Definitely work hardening the steel though. Need to cool it down. Either more coolant/cutting oil and or feeding harder to get those chips coming out.

 

[WaterH]

The saga continues.

I got 8 new 1/8” bits from McMaster today. 2 carbide and 2 fancy coated cobalt and 4 regular cobalt. More than $100 worth. I had two holes that I had started with my current bits. I decided to make it as easy as possible, so I heated both spots to a cherry red and let cool slow.

First, I started with one of the fancy coated cobalt bits. The plate on the floor on some 2 by 4s. A little bit of cutting oil. Started with the deepest hole. Got the drill spinning and pushed hard. It went right through in to the wood. Great!

On to the next hole that was just a slight divot. A little bit of oil and back at it. Maybe got an 1/8” and stopped throwing chips. Well hell, screw that, chucked one of the carbide bits. Drop of oil and leaned on it. It stopped short of breaking through. So I sharpened both drill bits. Both dulled immediately. I sharpened them again. This time I got a bride light on top of my grinder and a stool so I could sit there and spend some time. The cobalt is pretty quick to get sharp, but the carbide is weird. I sat there till feel I got it as good as can be. Dipping it in water after each grind to quench it.

Back to the hole that has only a 1/16” to go. I start with the carbide. It starts throwing chips and immediately shatters. I turn the plate over and pound it with a hammer. The carbide chips come out with a spec of a hole in the plate. I flip it back and drive the sharpened cobalt through.

So, two holes, one bit destroyed and the other no longer new. Like I said, I have at least 6 more holes in this stuff and I don’t even have these up to 1/2” yet.

I do have some bigger bits coming in coated cobalt.

 

[Dethmachinefab]

The carbide in a hand drill is not going to work well for you. You aren't ridgid enough to run it with a hand drill.

Thought you were going to put it in the mill?

 

[MigGunslinger]

I have one of those chinky mag drills. It sticks to metal and drills holes. The dovetails are extruded aluminum so I would not count on years of abuse but If you are going to beat the shit out of a mag drill for years you should buy a nice one.

No help on drilling AR500, that sounds like a job for somebody else.

 

[bgaidan]

So I got one hole out to 1/2”. Located it with a bolt and drilled the second hole 1/8”. Pull the whole thing out and mounted it on the mill.

Now just drill the second hole out to 1/2”, right. Easy right? No f ing way. The drills go right through the 1/4” angle (mild steel) and stop at the 500. Anybody that says they drill through this stuff with normal drills is a bull shitter.

Go back to this setup but use a center cutting endmill or even a 1/2" annular cutter.

 

[WaterH]

Next experiment.

Marked a new hole. Mounted plate in mill. 1/8” Carbide bit. High speed and lots of pressure. Drilled through most of it and then the bit shatters. A few pieces of carbide stuck in the hole. After much banging with hammer and digging with pick, have everything out. There is no hole, so it didn’t break through.

Took the previous dull cobalt and sharpened it. Was able to go through while fucking that bit. At least I had another 1/8” hole. This is the first time I didn’t anneal it.

I took my time and sharpened the 1/2” drill, turned it slow with some cutting oil. This time I decided to take someone’s advice and not go up in steps. It stopped making chips in less than ten seconds.

I sharpened it again and it immediately did not make chips. I took the plate out and torched the spot cherry red, let it cool slow and returned it to the mill. Re-sharpen the bit and try again. This time it went though in one pass.

It really didn’t like it, but it did it. Tomorrow I have some big cobalt bits coming, but I think the answer is anneal every spot I want to drill and then use the fancy coated cobalt. We’ll see.


Ps, anybody that says they can drill through this stuff not annealed with a normal drill bit , I have a thousand dollars against your hundred that says you can’t. (I am serious)

 

[ThePanzerFuhrer]

Why are we drilling holes in ar500 plate again? With the amount you spent in drills you could have had it cut out with a cnc. Plasma or laser.

 

[WaterH]

Why are we drilling holes in ar500 plate again? With the amount you spent in drills you could have had it cut out with a cnc. Plasma or laser.

I used the AR because I had it. At this point I could have bought mild steel probably for less than I spent on bits.

Plasma and laser don’t really cut accurate holes. The laser is probably good enough for this application, but I’m kind of OCD about things lining up. Anyways I don’t have access to either of those tools.

 

[muleskinner]

I don't want your money, but I just drilled through one of my 1/2 plates and videoed it for you. cheap Fastenal bit and a little Boelube. I'll upload it and post a link when its done. I have 10-12 plates of AR500 1/2'' thick I cut for long range targets.

 

[muleskinner]