Hey tools! I need your help finding a tool.
3I'm hoping someone here has an idea of what I'm looking for.
I need a 29-30mm hole saw bit that can cut through metal. I've ordered a few different hole saws off of Amazon - but they just don't have the bite to get through the metal without overheating. I'm currently using a knockout punch set to get the job done, but it could be way easier.
So - anyone know of a really great hole saw bit for metal? Or am I missing a really obvious solution?
- 12 comments, 20 replies
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I think you need to add some coolant to the situation... do you use any sort of cutting fluid / oil?
@thismyusername Not in this case. The smaller bits don't overheat.
@Thumperchick the cooling fluid works for both the bit and the target ya know :)
@thismyusername I do know. It's not the bit that sparks ya know.
@Thumperchick Couple thoughts: pick up some Tap Magic or similar cutting lubricant, extremely necessary to lengthen the life of your hole saws. Additionally, pick up a high quality, long life saw from McMaster-Carr. They have a wide variety of hole saws for a wide variety of prices, and in my experience can get the product to you within a day or two, depending on your location. They'll also happily sell you numerous types of Tap Magic depending on your application. I tend to just stock standard and use it on steel, stainless and aluminum of various thicknesses, though I've never used a hole saw on anything greater than MAYBE 1/8"
My added questions are: what material are you drilling, and how thick is it? Are you using a drill press or a hand-held drill?
@smigit2002 Drill press. Tin coated steel & galvanized steel. Less than 1/8", I want to say it's closer to 1/16" thick.
@smigit2002 I grabbed a longlife hole cutter from McMaster-Carr. Thanks for the help!
Bi-m etal hole saw a usually work pretty well, unless your drilling something hardened. Step drills also work well in sheet metal, but 29 mm might be too big.
@walarney I've used step-bits before. They do the job, but it's not as clean as I'd like.
Get yourself an itty, bitty, baby Horta. If I remember right, Hortas made perfectly round tunnels.
@Barney I'm mashing the star button, but it will still only give you one…
@Barney You are so wise, I am in awe.
@Teripie Yes, I am full of it. ;)
30MM is pretty big. Aluminum is actually tougher to drill than steel. Use windex to lubricate. What are you drilling through?
@tightwad tin coated steel & sometimes galvanized steel. Pretty thin overall.
@Thumperchick How thick? How thin is thin?
@lisaviolet The thickest is an old school mason jar lid.
Brian said to use lubricant, it helps keep the area clean. He asks how thick is the metal?
What I'm really looking for is a specific brand of bit that is known for getting the job done well, consistently. Is carbide coated the better tool for the job? Or would ceramic coated be better?
@Thumperchick He says fuck the coating, get one that's made with solid carbide.
@Thumperchick clearly you need a Kimla Streamcut 5D 5 Axis Waterjet CNC Machine.
OVERKILL FOR THE WIN!
@thismyusername mmmmm that looks like fun.
@lisaviolet Thanks! I'm going to give a carbide Klein bit a shot.
At work, the guys in fabrication use Morse advanced edge bi-metal hole saws for drilling into steel pipe (typically 0.1-0.25" thick); cutting fluid is to keep it cool.
Thanks everyone! I ordered 2 bits that should be good for my purposes.
Don't forget that speed (& feed) matters too, especially if you're already having overheating issues. Slow down for steel.
@retswerb @Thumperchick Scrolled down, hoping someone would say this. Very slow speeds of 200-300 rpm (or less!) will get the job done, even with a poor quality tool. Seems counter-intuitive, at least to me, but slow is the way. Edit: Good luck!
I don't think you will find a better method for home use than the knockout punch for such thin material, and rotating cutters will end up tearing the edges as they cut through. A step bit would be the only alternative, with the material clamped between a couple thin boards with holes big enough for the step bit to pass through (so a 45mm hole for instance).
Thanks everyone, for all of your help.
@lisaviolet - the carbide tip works like a champ!
@tightwad - windex works gloriously and it evaporates easily, which solved my concern about using a lubricant for this project.
@retswerb & @gregormehndel - I dialed the speed in and it made the cut go through even cleaner. I ended up dialing in a speed lower than the cheat sheet on my press.
@smigit2002 - You were right about how fast and easy it was to order from McMaster-Carr. Unfortunately the bit they sent wasn't the best tool - the seam on the bit was welded, but right at the cut edge, it wasn't closed all the way and it snags the metal while cutting. I'll hit them up for a replacement and see how it goes. Their shipping was super fast - though.
TL:DR - You tools helped me find the right tool for the job!
@smigit2002 - McMaster-Carr answered my email to them within 15 minutes and put a replacement in the mail the next day - free of charge - and let me keep both hole saws. The replacement tool is better, not quite the precision I need, but their customer service is top notch and I'll happily recommend them in the future.
@Thumperchick sorry to hear the tool didn't work out, but glad you had a good experience with McMaster!
@Thumperchick Slathered in Awesome Sauce. I'll have to try the Windex trick.