Drilling thick aluminum?

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I need to drill a 1.5" hole in a 1" thick disc of 6061. Will a bi-metal hole saw work with metal that thick?Also, I then need to cut the disc in half. Will a chop saw work? I know a hacksaw won't keep a straight cut.Lee TiltonSCCA F500 Pilot
Reply:Originally Posted by F500I need to drill a 1.5" hole in a 1" thick disc of 6061. Will a bi-metal hole saw work with metal that thick?Also, I then need to cut the disc in half. Will a chop saw work? I know a hacksaw won't keep a straight cut.
Reply:If you have access to a Plasma, I would just plasma cut it. Much faster and it can be done very accurately.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:I agree with Microzone about the plasma. But, if you have no access to one strong enough to punch through an inch of aluminum, a good holesaw will do the job. Like Zap said, clean out the chips. Try to keep the bit cool, and running straight as possible. If the bit gets hot, or wanders much, you will gall the bit up. It will bind, and glaze over the alum. as it goes, making it very hard to get through. Try not to get the speed too high. Use  decent downforce, and slow speed to keep the chips good sized.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by F500Also, I then need to cut the disc in half. Will a chop saw work? I know a hacksaw won't keep a straight cut.
Reply:Use the hole saw to drill the hole. If you have a small angle grinder you use a .045 zip wheel to slice it in half. If the piece is not too big just use a hacksaw._________________Chris
Reply:I use my bandsaw to cut aluminum.  blade not too fast and water as a lube to keep the chips out.  Works great till the wheels that drive the blade plug up with chips.  The blade is 18 tpi. X .020"  Sawzall works too if I go slow and use water as a lube or coolant.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Wow. Thanks for all the replies. It looks like a oft-cleaned, lubed hole saw is the answer. I will try a hacksaw for the straight cut.Lee TiltonSCCA F500 Pilot
Reply:I use my skil saw with a carbide tip blade. A piece of angle for a guide is nice too.
Reply:Hey F500,I concur with those who indicate a bi-metal hole saw. You will find WD-40 is amazing at keeping the teeth free from aluminum sticking. I use it for all my alum. cutting and as David R suggests, a bandsaw will give you the best results for alum. that thick....and also WD on the bandsaw blade will keep it free from cuttings....Good Luck....DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:What are the tolerances for this hole?How big is this disk?
Reply:Originally Posted by MAC702What are the tolerances for this hole?How big is this disk?
Reply:Good, hole saws have low tolerance, so I was making sure.You are cutting it in half as in slicing to have two thinner disks, or making two half-circles?
Reply:I would most definitely use a 1.5" twist drill before a hole saw in 1" aluminium ,nice and sharp and fairly fast with plenty of lube ..water based aluminium cutting fluid if you have it or WD40 will be OK though can affect future powder coating occasionally.Then cut on a drop saw with tungsten teeth , a timber drop saw as the RPM will be closer to ideal again plenty of lube and a slow but steady feed rate.
Reply:Originally Posted by MAC702You are cutting it in half as in slicing to have two thinner disks, or making two half-circles?
Reply:Originally Posted by BrettI would most definitely use a 1.5" twist drill
Reply:No a twist drill is a "normal" drill.  But a 1.5" twist drill would not be cheap nor easy to find, and I doubt you'd have anything that would turn it slowly enough.Do NOT use a spade bit for this, of course.
Reply:Originally Posted by MAC702No a twist drill is a "normal" drill.  But a 1.5" twist drill would not be cheap nor easy to find, and I doubt you'd have anything that would turn it slowly enough.Do NOT use a spade bit for this, of course.
Reply:This is a similar thing as to what I was referring to:http://catalog.starrett.com/catalog/...ec&GroupID=764
Reply:Interesting,These would be great for us at work http://www.ferret.com.au/articles/e1/0c0407e1.asp
Reply:Heck if anyone just happens to be wallowing in cash. http://www.hougen.com/cutters/cutters_index.html
Reply:rotobroaches are awesome. use them everyday my 3/4 is over year and a half old. it just keeps drilling hole after holebear
Reply:hole saw slow speed and parafin is a good to keep it going
Reply:I wonder how this would work? Especially if you continually stepped up like a 1/4" at a time? http://www.harborfreight.com/cpi/cta...emnumber=43776I ask because I have also experienced the innacuracy of hole-saws compared to smaller twist-drills, so I wonder if using these "silver and deming" bits would help.
Reply:Originally Posted by JMcDonaldI wonder how this would work? Especially if you continually stepped up like a 1/4" at a time? http://www.harborfreight.com/cpi/cta...emnumber=43776I ask because I have also experienced the innacuracy of hole-saws compared to smaller twist-drills, so I wonder if using these "silver and deming" bits would help.You can also use the hole saw by grinding away all the cutting teeth except for 4 diagonally opposite each other. If you grind the rest away giving yourself plenty of clearance and effevtively lengthening the remaining 4 cutting teeth then you will have no clogging worries. It does limit your hole saw by making it only suitable for ally but they are not too expensive. Two teeth left opposite each other would work just as well.Regards from sunny Cornwall__________________www.iancarey.co.uk
Reply:I'd use a hole saw and lots of vasoline... thats what I use.I own a 87 troopie (rust is slowly owning it  )I ride a quadand I love sticking metal together.  And I live in OZ...  (Geelong)
Reply:Originally Posted by sonamorYou can also use the hole saw by grinding away all the cutting teeth except for 4 diagonally opposite each other. ...
Reply:Originally Posted by MAC702Interesting.
Reply:Lenox has some hole saws that work nice:http://www.lenoxsaw.com/carb_hole_cutter.html