Punching 5/8 inch holes through .250" Sq Tube

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So here is a question just because I want to know. I have built plenty of trailer hitch receivers on trucks and such. I always place the square tube on my drillpress and drill out the hole for the hitch pin. Then you insert the drawbar into the receiver and secure with a hitchpin. My question is...How do you punch those holes instead of drilling? Do you punch through both sides of the square tubing at once? Or do you punch one side and then the other....which creates another question...how do you align the two holes if done separately?I want to build a press that can punch these out. But I want to know how it's done first! I know, it will take longer to build the press and punch than to just drill out another tube....that's just me.Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:Mechanically I'm not sure how it is done though I could imagine.    I could also imagine (right now) that a .45 might punch the holes for you.       Of course size and position will be tricky A decidely non mechanical way would be to use an EDM machine.     Actually sitting here I did imagine one solution to the punching problem.    That woould be to use an insert in the tube as part fo the die.    Then punch through that on one side and continue all the way through into the ohter side.    I do not see punching as a reliable way to put the holes in place.    A better laternative would be to drill throgh both sides in one shot in a drill press with a square table.   ThanksDaveLast edited by wizard; 04-27-2006 at 08:40 PM.
Reply:Originally Posted by wizardMechanically I'm not sure how it is done though I could imagine.    I could also imagine (right now) that a .45 might punch the holes for you.       Of course size and position will be tricky Dave
Reply:I drill a lot of 5/8" holes in square tubing.  Usually 2" x 1/4".  If I were going to make a punch I would first blast through it with a 1/4" bit in a drill press.  You would then have a hole in the same position on both sides and be able to align your punch.  It would be a good idea also if you are inserting something in the tube to drill through that at the same time.  Normally when I drill out the holes I go 1/4", 5/16", 3/8", 1/2", and then 5/8".  The drill doctor is setup at the drill press so I always have a sharp bit.Neil
Reply:Back when I was young, dumb, and full of you know what, I always would ask "how do they really do this?".Since then (which is not to say I am no longer dumb and full of it, just that I am no longer young) I have spent 30 years or so scanning catalogs, reading old technical books that I bought at used bookstores, and sticking my head in dirty fab shops.And so I found out how they do this.Its called piercing, as opposed to straight punching, and it is often done with a special die in a punch press or hydraulic press.If you go to this website, and scroll down to the second tool, you will see a dandy item you can buy that will punch a hole simultaneously in both the top and bottom of a piece of square tube, anywhere you want it along the tube. Like magic.http://www.vogeltool.com/piercing.html
Reply:If you can avoid it don't drill through the side that has the weld.  It makes for a bad experience.  Drilling with a large drill press having power feed is the way to go in my view.
Reply:Ries,Thanks for the link. That is cool. But it doesn't really address getting a non dimpled hole top and bottom. According to their web page, it either can't be done with their tool, or a custom die set is required. Anyway, I just wanted to know, but I guess I will continue with my drill press for the time being as it has never failed me.Thanks for all the other replies too!Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:I don't think you would be able to punch it without collapsing the tube.
Reply:Me prefer drill press idearIF it Catches...Let it Burn
Reply:A drill press ought to do fine.    If it is manual feed do consider drilling a small pilot hole though one side before following up with a 5/8" drill.    This of course depends on how much horse power you have available and the quality of the drive mechanism.If you are having trouble with feeding a 5/" drill through virgin metal you may also want ot look at an alternative grind on the bit.Dave
Reply:Actually, they do it all the time in industry without collapsing the tube.Besides the piercing dies I linked to, there are also setups to punch holes in square tube with an ironworker. They use an inside mandrel.Here is link to another company that does it.http://www.tubepunching.co.uk/SQUARE...are_tubes.htmlBut obviously, you are talking a bunch more money. The tooling must be precisely made, of hard steel, heat treated, and used in a big, powerful press.For drilling, on any hole over 1/2", I use rotobroach style annular drill bits, the kind that Hougen and Jancy make for their mag drills. These are kind of like super duper hole saws, with carbide teeth. Available in 1" and 2" depth of hole, they work great as long as you clamp the material well in the drill press, use a lube or coolant, and run em slow. I have drilled literally hundreds of holes in 5/16" stainless plate with these- they work great. You can get em at most welding supply places, or direct from Jancy or Hougen or Milwaukee. They are resharpenable, for 15 bucks or so, and last forever if you keep sharpening em.lots easier than a big twist drill. Much less metal is removed, so your drill does less work.The problem with most home size drill presses is the chuck is just pressed onto a taper shaft, and with a big 3/4" twist drill, its easy to overpower that connection, and have the chuck spinning free in space. A real drill press meant to handle large twist drills, like a radial drill, can easily weigh 4000 lbs and cost ten grand.
Reply:Those are the coolest tools to have. Unfortunately a little to elaborate for my shop. I am sure that I could use something just like that to do the job. I need a salvage yard here in Arizona like the ones up in Denver. Man, they had a lot of hydraulic press stuff. There must be some tool out there that would be simply a manual setup in an H=press to do what I want to do. But like I said....my drill press is working just fine. Thanks guys! I need to check out those drill bits you mentioned now.Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain