What plating is safe to weld

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The pedestals for my new lathe are too narrow for the load, and I don't want to bolt them to the floor, so I'm widening the stance with some heavy 2x2 angle iron.The angle will lie flat on the floor with 5/8-11 studs that will protrude up through the base of the pedestals.I was going to use flat head bolts (the object is to have the head of the bolts flush with the surface), but the counter sink for  5/8 flat head bolts will remove a lot of material, and presumably some strength.Now I'm thinking of just welding some 5/8 threaded rod, or bolts with the head removed, into the holes. Needs to be strong enough to avoid pull-through and keep the bolts from spinning while tightening the nuts.I'm a newbie welder (taken two classes at the local community college), and need to know which all-thread/bolts would be  safe and/or suitable to weld into the hole. I know galvanized is out and I've never welded stainless. This leaves grade 5 and grade 8 bolts and what ever material common all-thread is made of.1. What plating should I stay away from or should I just grind it off prior to welding? I should add I do have some fume extraction capability.2. Will annealing from the welding heat significantly reduce the strength of the all-thread/bolts?Last edited by jmarkwolf; 03-18-2016 at 08:25 AM.
Reply:Since you are going to have something to trip on anyway, why not use like 3" channel? You can mount with standard bolts without welding(open face down). As for fumes, if you have good fume extraction, most anything should be okay except for cadmium but I don't think it is supposed to be used here anymore.  What are you welding with? If you are stick welding even stainless shouldn't be a problem. You can buy a few rods. Mig might be a bit more expensive.   IMO in the heat affected zone strength of grade 5 & 8 bolts will be affected negatively.---Meltedmetal
Reply:Buy 5/8-11 set screws from McMaster-Carr and thread them into holes you've taped in the angle iron. Apply JB Weld to the clean threads and you won't need to Weld anything. If you really want to weld something, buy unplated bolts.
Reply:Thanks for the response Meltedmetal.I want to use angle iron because I don't want to raise the height of the lathe any more than the thickness of the angle and any shims required to level the lathe.Will be knocking off the "corner" to reduce tripping hazard, and maybe painting them caution orange.My fume extraction is DIY but employs an honest 300CFM radial blower exhausting outside the bldg. Works pretty good.I have a Millermatic 211, previous style, not the latest converter model.In your opinion, would it be better to have strength compromised by heat affected zones, or removal of material due to counter sinking flat head bolts?Last edited by jmarkwolf; 03-18-2016 at 09:21 AM.
Reply:Sorry  I'm so long in replying I must have missed your reply somehow. Just got a notification by email. If I was going to weld them I'd probably use unplated grade 2 bolts(they are pretty much mild steel) and cut the heads off and countersink the holes from the side where the heads would have been to get full penetration. Almost any method that has been described should keep your lathe upright. It's not mobile is it? I suppose, depending on  how the pedestals are made you could bolt the other way with the bolts parallel to the floor, might have to use a spacer or two.---Meltedmetal
Reply:i'd use a grade 8 and strip the coating with muriatic acid.
Reply:http://www.portlandbolt.com/technica...le-nut-grades/This refers to nuts but I would assume that the same thinking would apply to bolts.And this is what they say about bolts.http://www.portlandbolt.com/technica...-anchor-bolts/Last edited by Meltedmetal; 03-20-2016 at 10:19 PM.---Meltedmetal
Reply:Excellent info everybody.Here's what I decided to do.A lot of material would've had to be removed in order to counter sink 5/8-11 flat head bolts, so I decided to mill down the heads of some hardware store grade 2 or grade 5 bolts (don't know which) to 0.125in, and counter bore the angle iron 0.125in to accomplish a similar thing, while removing less material from the angle iron.The heads of the bolts will be heavily tacked to the angle iron to prevent turning and provide some extra strength against pull-out. Tacking should prevent too much heat-related loss of strength in the bolts.As a system, the angle iron is just there to help prevent tipping. In order to fail, the 2in x 2in x 1/4in by 24in long angle iron would have to buckle, or the heads of the bolts pop off. And I can't see that happening unless the lathe were to be dropped from some height or knocked over with a hilo, neither of which is going to happen in my home shop (barring an earthquake, but then all bets are off anyway).I had to mill some slots for wrench access to tighten the nuts (see pics below), which compromised strength somewhat, but there's always compromises. The lathe weighs 1000lbs. Dividing this force by the 4 pieces of 24in long angle iron, on each side of two 14in wide pedestals, equals only 125lbs per end. Can't see the angle iron buckling under such little force.There will be shims under the ends of the angle iron for leveling purposes, and under the middle to prevent "drum-heading" to help support the weight. The bolts won't be torqued to spec, only tightened enough to compress the lock washers, and a little "extra".The "footprint" of the "bare" pedestals are on the small side, but many people use them as-is with no extra precaution. Some people bolt them to the floor, and if my angle iron "outriggers" don't provide the expected stability, I can still remove them and bolt the pedestals to the floor.Anybody see a fatal flaw in my logic?Below is a pic of the reduced head of the 5/8-11 bolts:Below is bolt in place prior to tacking:Below is a trial fitting of one pair of the outriggers (note: the pedestal is upside down):
Reply:These are the standard bolt head markings.https://www.boltdepot.com/fastener-i...ade-chart.aspx I don't think you should have a problem but I probably would have been one of those that used them as is. You might want to plant your trash can or something tall in between each pair of angles to make you walk around them though. Enjoy your lathe.---Meltedmetal
Reply:Originally Posted by MeltedmetalThese are the standard bolt head markings.https://www.boltdepot.com/fastener-i...ade-chart.aspx I don't think you should have a problem but I probably would have been one of those that used them as is. You might want to plant your trash can or something tall in between each pair of angles to make you walk around them though. Enjoy your lathe.