Weld distortion 1.5" plate

admin

Some of you may have read in the cutting/machine tool section that I have a 1.5x48x48 plate that I was planning to put 133 1/2 13 threaded holes in.  The more I think about hand tapping that many holes that size and that deep the less appealing it gets.  In fact, it sounds downright miserable.  I got a wild hair and started thinking maybe I'll just drill the holes 5/8" and just tack weld a bunch of unplated 1/2 13 nuts to the bottom of it.  I'm having the plate blanchard ground, and if I go this route, I'll have to tack all the nuts after grinding.  Assuming 133 nuts, say 2 3/8 tacks per nut, that's 99 3/4 inches of weld on the under side of this thing.  If I take my time and skip around the plate, maybe set the welder a tad cold, and take my sweet time, can I expect much distortion?  I'd hate to have to have it ground again, probably cost quite a bit more in set up time having to put it up on parallels and what not.  Didn't mention earlier, but yes, this is going to be the top to a welding table, so the 1/2 13 holes will be for use with mill toe clamps, and the 5/8 hole will let me adapt some strong hand tooling as well.
Reply:Originally Posted by ARexpatSome of you may have read in the cutting/machine tool section that I have a 1.5x48x48 plate that I was planning to put 133 1/2 13 threaded holes in.  The more I think about hand tapping that many holes that size and that deep the less appealing it gets.  In fact, it sounds downright miserable.  I got a wild hair and started thinking maybe I'll just drill the holes 5/8" and just tack weld a bunch of unplated 1/2 13 nuts to the bottom of it.  I'm having the plate blanchard ground, and if I go this route, I'll have to tack all the nuts after grinding.  Assuming 133 nuts, say 2 3/8 tacks per nut, that's 99 3/4 inches of weld on the under side of this thing.  If I take my time and skip around the plate, maybe set the welder a tad cold, and take my sweet time, can I expect much distortion?  I'd hate to have to have it ground again, probably cost quite a bit more in set up time having to put it up on parallels and what not.  Didn't mention earlier, but yes, this is going to be the top to a welding table, so the 1/2 13 holes will be for use with mill toe clamps, and the 5/8 hole will let me adapt some strong hand tooling as well.
Reply:Get a big milwaukee mag drill and drill and tap them
Reply:I saw some drill bits on another post somewhere that had a tap built into the shank of the bit...  That might be a good option if you can find a 1/2".Like this - http://www.amazon.com/dp/B003JY6IMI/ref=biss_dp_t_asnLast edited by AKmud; 05-02-2014 at 11:29 AM.Miller Dynasty 200DXMiller 252 Miller 250xMiller Syncrowave 250Miller AEAD200 LegendMiller 375 Xtreme plasmaLincoln WeldPak 100Victor O/A
Reply:Couple reasons, I'd rather spend 20 dollars for 150 nuts than 20 dollars or more per tap, with the nut recessed into the hole a 1 1/2" there'll be less chance of a hot dingleberry wasting out the thread, and in the event I do tear one up past the point of re-tapping, I can always just delicately cut it off and pop a new one on.  I am planning on using annular cutters with a rented mag drill.  Sounds like I'm building something pretty similar to yours.  What do you do to protect the threads in your table?  I thought about putting in set screws just below the surface but that sounds like a PITA to deal with.  How do you keep the berries and general crap out of yours?  This isn't going to be one of those "I only tig on it" tables.
Reply:Originally Posted by ARexpat I thought about putting in set screws just below the surface but that sounds like a PITA to deal with.  How do you keep the berries and general crap out of yours?  This isn't going to be one of those "I only tig on it" tables.
Reply:I say nuts welded on the back.You may decide you want to change bolt sizes or something later on.Just think of all the taps you will save.Knowing my luck if I needed to chase a thread hole I wouldn't be able to find the tap again, or I would have broke it doing something else and forgot to replace it.Just drilling each hole, sharpening the bit every 2 or 3 holes is going to take long enough, sounds like machinist's hel.In case you were wondering, having deep thread channels wont make the bolt hold any tighter or stronger. The first 3 threads hold 90% of the load on the bolt. A 1/2-13 bolt with 6 or 7 threads will be more than sufficient.old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:Drill and weld nuts. Less time, tooling, and aggrivation. If you go the other route you are likely to break a tap off in a hole at some point in the process.  Not easy to extract a tap.GravelThe difference between theory and practice is that in theory there is no difference.
Reply:Mag drill for holes and a good tap in a cordless drill would make that a piece of cake.  I'd bet a good spiral point tap could be run clean through and retrieved from the underside rather than backing it out.My name's not Jim....
Reply:What are you planning to drill these holes with?  Drill and tap gets my vote.  You could stagger/alternate your 5/8 holes as well. Get a good tapping fluid and keep your tap square,  you should be able to get through them all without issue. I use moly-dee (Castrol product) for everything but aluminum and copper.
Reply:Shovelon, what do you keep the holes lubed with, and does it ever contaminate a weldment?  I already said I'm planning to mag drill with an annular.  The idea behind tacking nuts rather than tapping was 95% driven by the serviceability of the hole, more protected from BBs, easier to replace if wasted out.  I thought about just filling the threaded holes with nozzle gel, but it seems like it would have to get touched up often, for instance, you couldnt just indiscriminately give the surface a rub down with acetone without losing some of it.  Thought through the whole allen set screw just below flush idea, sure that would protect the thread, but then wouldn't I just trade that for BBs stuck in the allen hex?  I also thought about not tapping the holes completely through, kind of the same idea as t nuts not being threaded completely through or staked at the bottom to keep the stud from continuing down when you tighten the nut on it.  Plus it'd save me some cycle time and probably a few taps.  I'm not too concerned about breaking a tap, I'm not enough of a shop gorilla to go snapping off 1/2 13 taps like its a 6-32.  Not saying it can't be done though.  Oh well, I keep flip flopping back and forth between the two ideas, tapped hole or tacked nut.  The 5/8 hole is looking less appealing, as the stronghand tools that are made to insert in the 5/8 hole look like junk.  I've got some of there bigger heavy duty clamps that I like even more than my besseys, but those little inserta clamps that are meant to go with the build pro are pretty weenyish.  So there's another +1 for the 1/2-13 holes and homemade tooling...
Reply:If you want to,  or drill the first inch to 5/8" and then drill through with the tap sized drill,  and tap the hole,  or drill the smaller hole first and drill out the top inch, taping the bottom 1/2 inch,
Reply:That'd actually work as far as getting the threads hidden down further to protect them better from the BBs but with an annular cutter I don't know if that would work very well.  The tap size cutter would be cutting for half of the hole through the leftover slug from the 5/8 sticking up, and that would probably chatter or knock it off center somehow
Reply:Originally Posted by ARexpatShovelon, what do you keep the holes lubed with, and does it ever contaminate a weldment?  I already said I'm planning to mag drill with an annular.  The idea behind tacking nuts rather than tapping was 95% driven by the serviceability of the hole, more protected from BBs, easier to replace if wasted out.  I thought about just filling the threaded holes with nozzle gel, but it seems like it would have to get touched up often, for instance, you couldnt just indiscriminately give the surface a rub down with acetone without losing some of it.  Thought through the whole allen set screw just below flush idea, sure that would protect the thread, but then wouldn't I just trade that for BBs stuck in the allen hex?  I also thought about not tapping the holes completely through, kind of the same idea as t nuts not being threaded completely through or staked at the bottom to keep the stud from continuing down when you tighten the nut on it.  Plus it'd save me some cycle time and probably a few taps.  I'm not too concerned about breaking a tap, I'm not enough of a shop gorilla to go snapping off 1/2 13 taps like its a 6-32.  Not saying it can't be done though.  Oh well, I keep flip flopping back and forth between the two ideas, tapped hole or tacked nut.  The 5/8 hole is looking less appealing, as the stronghand tools that are made to insert in the 5/8 hole look like junk.  I've got some of there bigger heavy duty clamps that I like even more than my besseys, but those little inserta clamps that are meant to go with the build pro are pretty weenyish.  So there's another +1 for the 1/2-13 holes and homemade tooling...
Reply:Right on.  Well I guess I'll pick up some hss taper taps and give the arms a good workout, for 133 holes what do you think, 2 or 3 enough?  I'll pick up some of the dry film lube you suggested and see how it works for me.  After I have this table in service for a while and figure out what worked and what didn't, I'm going to build a brother for it so I can push them together and have a 4x8 foot surface to work off of.  Leveling pads and all that
Reply:Nozzle dip for a MIG gun works well to keep crap from sticking in the holes and shouldn't contaminate anything.Miller xmt304,  Miller S22 p12, Miier Maxstar SD, Miller 252 w 30A, Miller super32p12, Lincoln Ranger 9, Thermal Arc 181I with spoolgun, Hypertherm 10000 ,Smith torches. Esab 161lts miniarc.