Hot Rods hole saws keep dulling.how to cut holes in metal

So I got my mitler brothers hole flare,and a hole saw.figured I get 100 holes out of.it.....wrong,first Irvin whole saw when dull after one cut.second lenox saw went dull after 4 cuts.I can't exactly afford a nice punch die,what's the best option? My visor is halfway drilled as I speak and it drives me nuts..I used wd40 while cutting with the hole saw...didn't help

 

You have to turn them slowly, too much speed and they will die a quick death. I blow on them with an air hose to keep them cool, I never use any lube. The lube just turns the chips into a metal shaving soup and wont cool anywhere near as well as the compressed air.

 

Super hard to drill slow on an angled visor with a hand drill.these saws just seem like a crap way of doing it.my dimple die is bored waiting! I'll try one more time with yet another saw and see if I can go slower.I plan on doing my visor,door panels,and bomber seats with it

 

I'm a little confused, don't you just drill a hole for the bolt that draws the two sides of the flare together and make the flared hole. What's the hole saw for?

 

A dimple die doesnt punch the whole

 

If you are cutting a bunch of holes the same size look at a carbide tipped hole saw like the one Champion makes. When I was doing commercial kitchen stainless they were the only way to go. Way cleaner cutting than a traditional style. Got 30 or so holes with them in SS and maybe 1 or 2 with a Lennox.

 

So I'm not the only one having this problem then I take it.I'll look for that.I spent some doe on a nice dimple die so I plan on doing a bunch of holes in that size

 

I do mechanical pipe fitting work, and I've drilled at least a 100 holes with a single hole saw. Just need to keep the speed on the slower side and keep a decent amount of pressure on it, along with cutting oil.

If the electricians happen to be around then I'll use their hydraulic punch kit, greenlee or ridgid I believe. So if you have any electrician buddies that might be an option?

Ever notice how a hole saw will go through 1/4" steel on a drill press like butter? Over and over again? Slower speed and pressure

 

I think some hole saws are made off shore for sure. I have used a blumol hole saw on panel steel and it was brilliant. But went to cut a hole in a trans tunnel for a speedo cable with a no name cutter and was cutting away or so I thought , heck this is taking a long time , ok the teeth are pretty much gone. Cutting slowly etc. was this one designed for wood or just cheapo junk.
A hole punch was a much better option cutting a hole in the trunk floor for a battery cable.

 

I wish I had a hole punch.but that's way too much doe right now.I don't know any electricians.

Lenox isn't a cheapo,Irwin is sorta(vice grip brand).the lenox was 18$

 

I have heard good things about Bluemol saws, Home Depot carries them. Thanks for the reminder Kiwi 4d.

 

Too much speed and/or not enough pressure if you're burning up Lennox hole saws; Greenlee makes a good hole saw too, Irvin are junk. Also using a specialized cutting fluid like Rapidtap can help; WD40 just makes a smoky mess.... Like Hambone, I've got hole saws that are 10, 20 years old that still work just fine. They do tend to dull just a bit after the first 5-6 holes, but will still cut fine with a bit of increased pressure. The high-buck carbide saws need exactly the same use and care, but really prefer a rigid setup (like a drill press); it's pretty easy to chip the carbide using a hand-held drill.

But KO punches are really the best way to cut clean, multiple holes in a pattern as long as the holes are on a reasonably flat surface. Here's a good price on a quality Greenlee set... http://www.zoro.com/i/G1705137/?utm...hopping_Feed&gclid=CKa5593wqcQCFcVhfgodFnQACQ
Note that these are conduit 'trade' sizes (1/2, 3/4, 1, 1 1/4"), actual sizes are 7/8, 1 1/8, 1 3/8, and 1 5/8".

 

Check with your local rental center. They may have an electrical cutter set you could rent. If you weren't on the other side of the country, I'd let you use mine.

 

Floppy sheet metal is hard on the bit, they will cut better on the drill press


the bigger the diameter of the hole saw, the faster the tooth speed will be for the same shaft RPM. A gear reduction drill will help slow you down but it will still be too fast for steel.
For example, 280 rpm will be screaming for a 3-1/4" hole saw in steel and about the $$$$ slowest $$$$ hand drill you can get will about 400 rpm. Wd40 isn't a good cutting fluid, it's better than nothing but just a little.

If I were doing 100 holes in sheet metal with a hand drill any larger than 2" I'd surely get a punch die

 

Another tip (once you get your speed under control) is to drill a 1/4" pilot hole, then use a piece of 1/4" rod in the hole saw instead of the drill bit. This
seems to pilot the saw better, especially in sheet metal. I usually use a thick
cutting oil, messy; but does the job.

 

also if you back it up with a piece if wood. keeps it from flopping
use cutting oil not oil. you do not want to lubricate. cutting oil cools

 

Cutting oil is the only way to go.http://en.wikipedia.org/wiki/Cutting_fluid

 

I did use wood behind it

 

C R L or most commercial glass shops sale a metal drilling\ cutting wax, one tube should last you for years. less messy and faster clean up than oil..wd 40 won't cut it

 

Drilling holes with a hole saw is a lot of fun isn't it. (not)
I know what you are going through.
We just did three yesterday. Started out using my inexpensive drill press.......it didn't have enough power and would stop under to much pressure.........switched over to an electric drill. Wood behind the metal held in place on the vise.
It was still a struggle but managed to get all three.
Seemed like constant lower rpm's and equal pressure did it. Didn't use any lube.
Good luck!

 

x2 I just did my visor about two weeks ago using a hole saw I've cut at least 100 holes with prior. Thought I was in for a fight but they went like butter, as soon as I slowed the drill press down all the way. Was done in half an hour and nice round holes. With the drill press you can exert enough pressure to flatten out the visor curves against a wood backing and get an even cut so the circle breaks through at the same time.

 

There are tons of Greenlee knock out punches on Ebay at very good prices.
KO punches will save you lots of $s in the long run.
You will get a much cleaner hole also.
KK

 

Using a holesaw can be challenging. If it squeals real loud, you will probably burn it up from not enough pressure. If to much pressure it will probably stop turning. There is a fine line between too much and not enough pressure (feed). Good luck. I'm sure many of us have burned up a few before getting it right.

 

I always use cutting oil and a high quality hole saw (Champion) is a pretty good one.

Even pressure and never try to power through what I'm drilling. HRP

 

Greenlee knock-out punch, bolt type

 

Most of the hardware store brand hole saws are only good for wood. You need a high quality saw.
WD-40 won't help much. Use Plumbers lard, Tapfree, Mobil 102 or any other good cutting fluid.
A slow speed drill press with lots of torque. If you have to use a hand drill, make sure it's a 1/2" variable and have a helper to pour coolant while you slowly drill.
It also helps to rotate your hand slightly so that only about 25 percent of the hole saw teeth are in contact with the metal rather than 100% of the teeth at once.
Better yet, invest all that blade $$$ and buy a used knockout punch in the size you need and be done with it.

 

I have made several 2.5 dia holes in 3/8 steel with my Starrett hole saw. On the bridgeport. Still cutting. When i was a kid i wanted to make 10 two inch holes in my deck lid on a drag coup. I ended up using a brace and turning the saw by hand. But that was 50 years ago. Most won't do that now.

 

My hole saw, just the regular old thing you stick a 1/4" drill bit through, has a hex top on it that fits in a 1/2" chuck. Saving grace, if you try to spin it with a 1/4" shaft (never use the drill bit after you've drilled a pilot hole) the chuck won't hold it.

 

I know it's a little late now, but Mittler Bros. sells dimple dies, and flaring punches.
The flaring punch makes the hole and the flare at the same time. I have a couple of them,
and they work very well.

 

I use Milwaukee hole saws with an air blast on my drill press. I try not to use them in a hand drill, because you can't push hard enough to make them cut. A trick you can try is to remove half the teeth. you can't just take out every other tooth because of the set, but remove pairs. half as many teeth equals half as much force required.