Welding nuts or bolts to metal

[Glenn]

Let us say we want to weld a nut in place against a piece of metal. The nut would then be used to receive a bolt to hold parts together.

Do you position the nut by just placing it against the metal, or do you put the bolt in place with the threads only flush and weld, using the bolt to align the position and placement of the nut?

Do you need to do anything to the bolt to keep it from sticking to the nut from the heat? Do you take the bolt out while the weld is still hot, or let it cool before you remove the bolt?

Is it best to weld on one flat (one side) of the nut, two sides, or a full weld encircling the nut?

Just trying to get some opinions on how YOU would do it.

[MooseRidge]

Normally, I whittle down a stick and screw the nut on until its flush, then two spot welds on either side for placement. Then full weld around the nut. If the stick burns, no biggie.....

[the_sandy_creek_forge]

Kinda carried over from the welding spatter thread. I never-seize the whole bolt, put it in place and wipe off any never-seize that will get in the way of the weld. Helps the bolt release from the nut AND keeps the spatter off of the threads. I usually just weld on two opposite flats, but have welded around the whole nut depending on the application. And ALWAYS ALWAYS ALWAYS grind off any coating that is on the nut or bolt before welding. ALWAYS.
-Aaron @ the SCF

[rthibeau]

nice tip about the stick Moose.....I've always used a bolt in the nut to position the nut and keep it's thread clean, then welded all the way around the nut....then took out the bolt and half the time threw it away. Usually tack weld the nut in place, remove the bolt, then finish welding all around...I use a mig

[hammerkid]

like Aaron said i always clean/grind the coating off before welding! but most of the time i drill & tap it

[Finnr]

I weld all the way around a nut with a bolt in place to keep the threads clear. I use duct tape on the bolt so I can save it.
Finnr

[GrandLordKhorne]

First of all, I’m careful not to use any bolts with a coating (like cadmium that will hurt you if you weld it). But I tend to put the bolt in, tack it, take the bolt out and complete weld all the way around. I have yet to get spatter in the threads on the inside of the nut. Having said that, if I’m welding a bolt/stud to a part, I always cover the threads with a piece of tube or something to keep the spatter off.

[jayco]

Mooseridge's tip about using a stick to hold the nut in place and keep splatter off the threads is a very good one.

I recall several years ago doing a repair for my father-in-law that required welding nuts in place.He picked up a stick and did that very same thing. I hadn't thought of that idea.Seems that when I'm welding, I think of metal........not sticks.

[chrispinnh]

In my experience , its almost easy with the size of bolts we use. I have done structural steel for over twenty years. With structural pieces and stairs we would sometimes have to tack on nuts for a blind connection , usually tight in a corner where the wall prevents the connector from getting a hand in behind to hold a nut. The size we use is almost always 3/4 inch bolts and nuts.
I use a 3/4 inch flathead bolt , set-up for a countersunk hole. It has a round head , and is set-up to be used with an allen wrench. Our holes are usually punched , if not I drill the holes , then put the bolt in with the tapered head on the opposite side of where you need the nut , the taper will center the nut in the hole. I just hand tight the nut , just to keep it from wobbling. Then a little shot of spatter spray , I weld two opposite sides of the nut . I dont need an allen wrench to loosen my bolt , because i welded a handle on it , it gets hot after a couple of holes. Hope that helps......c

[aametalmaster]

Lets say you have a 1/2" hole and you want to weld a 7/16" nut centered on it. If you had a lathe you could turn a stub to stick thru the hole from the backside with a small 1/2" shoulder to line up the hole then the stub would have a small end turned to fit the ID of the nut and the same height to hold the nut while you tacked it. Thats how we did it in the sheetmetal shop when we had hundreds of holes to do and they had to be perfect...Bob

[Glenn]

A tapered drift should aid in alignment.

[Ten Hammers]

Lets say you have 3/4" pipe and a hole drilled in it (next sized over 3/8). Take a setup bolt ( 3/8 x 2 ) and put a nut down to the bottom of the threads. Dip the exposed threads in some vaseline or whatever you use for nozzle gel. Place the bolt through the hole and place another nut in the end of the pipe and tighten the nut thus holding the bolt tight in the pipe. Set the bolt paralell to the table and make down welds on the outside nut from each side. If you have a hundred of these to do, the man may object to your procedure ( time ). Then you do same ( nut on bolt to bottom of threads, then dip in grease ). Take a pair of # 17 t vise grips and weld a piece of angle on the bottom jaw ( to recieve the pipe ). The top jaw goes on the bolt head and close the clamp. This holds the bolt firm in the pipe and weld as noted. Remove the bolt with a pair of pliers. This actually works better than the nut inside but you need dedicated clamp for the procedure or grind the angle off. IF the weld makes it into the threads you may work back and forth with a wrench to save the nut. Experience will tell you how big of hole to drill for the bolt to pass through. If you need to put a nut on the corner of a piece of square( for strength ) you can make passes on the edge of where the nut will be welded ( since you have exposed threads that are hard to not weld). Let the color go from the weld and then make another pass to the nut thus attaching the nut and not welding the threads. You can also try and tack to the outside of the square corner to hold the nut first. USE grease( whieither nozzle gel or Vaseline) to dip the threads. Yes it will smoke. All in your needs. A pipe clamp ( call them Pony if you wish ) with the sliding end removed is helpful for plate. Make the pipe 6-8" long ( for a very short clamp ). Black pipe. Keep this for many shop uses. Remove the sliding end and tack the pipe beside the bolt to be held ( tack on the bolt side ). Unscrew the clamp and place a piece of rod or square from your collection between the clamp and the bolt head. Screw the clamp tight to hold the bolt/nut down to weld ( this is out of position issue that works nice ). Twist the pipe to remove and grind. PUT THE SLIDER BACK on the pipe ( I never lose stuff do you ? ) As noted a piece of broken pallet or whatever else will hold the head of the bolt down if gravity or position is in your favor. Sometimes you just got to Clampett, Jed.

[pete46]

Clampett Jed !
I Hate That I'm Old Enough To Get That Joke!
Well Got'ta Get To The Cement Pond For The Turtle Race!

[Ten Hammers]

I also might add that if you have an issue for centering, wheel bolts ( or studs ) and nuts work nicely. The back of the leg vise in the shop is mounted to the table with them ( studs through plate from the bottom and nuts on top, plate then welded to table ). Alignment of holes was critical to keep plate square for good joint to weld but fairly close worked nicely. I'll rustle up a pic if I can.

[sstreckfuss]

I weld all the way around a nut with a bolt in place to keep the threads clear. I use duct tape on the bolt so I can save it.
Finnr

I use the exact same method except I use masking tape in place of duct take, we don't have duct tape laying around the shop or I would probably use it.

[pawhiker]

Hi, i'm not an expert welder, (x is a has been and a spurt is a drip under pressure) just a creative guy. I had some problems stick welding (3) 1" nuts to 2" angle iron 3 1/2" long. This is supposed to spin smoothly but after I welded them it nearly impossible to turn the bolt rod through them. I intend to weld another 2" angle to create a rectangular box which I am making into a slide that moves between two other pieces of angle. Can I heat up the three nuts and angle to correct the struggle? I think the angle got twisted from the heat. If I heat it up and run a rod through while still hot will that relax the nuts ?   I clamped the three nuts to the angle with a rod through them. There was about 1/2" space between the nuts.

[John McPherson]

Another victim of the "More is Always Better" school of welding.

Overkill is not your friend in a case like this. Welding all around is massive overkill, and the weld puddle will shrink and constrict the relatively soft metal of the nut. Your only response at that point is to use a blind tap to repair the threads. Multiple welds, all on one side to attach multiple fasteners will warp the base metal, especially if it is a small mass without some sort of restraint, when all three attachments are welded in a short time span. 

Welders need to learn the Hippocratic Oath 'First, do no harm.' Whole books have been written on flame straightening and warp prevention and repair in the weld shop and in the field. 

The fix: Use just enough weld to hold the nut in place, a small tack on three of the six sides. Let the whole piece cool to the point that you can pick it up with your bare hand before you attach the next nut. Not fast, but more precise.

If you have multiple welds to do on the same piece, try skip welding. The same school of thought that you use when changing a wheel on a vehicle: hand tighten the nuts 1-3-5-2-4, and then snug them down with a second pass in the same order to better distribute the stress.

[pawhiker]

 

Thanks John..... I think I over did it....I tapped it on the anvil and it got a smidgen better but it never spins like it did in the beginning. Two of the nuts were very hard, maybe #5 or #8...I may try it again with new parts. I tend to over-build everything so I have to watch more closely. Thanks again...

[arkie]

When welding a nut to another piece of metal and you are using a screw or bolt to hold it in place, align it or keep the nut from deforming, here's a tip:

Put the ground clamp on the workpiece (metal base), the same conducting path as the nut...not on the bolt.  If you place the ground clamp on the bolt then weld the nut, there is a chance that you might get some arcing from the bolt to the nut and thereby forming a spot weld between the bolt and nut.  I had this happen and had to break the bolt loose and chase the threads with a tap.  Large taps are not in everyone's tool box and they're expensive.  The bolt and nut never worked very smoothly after that.

[AJtheWelder]

coming from an Ironworker, never ever weld without soaking a nut in some acidic liquid wiping it off and grinding the surface you are to weld, and to make it easier to weld instead of placing it flat on the plate bevel the side that goes into contact with the plate to make a groove about 1/16" and stick your wire or electrode in that grove and follow it around. also never place your ground on the bolt, place it close to the nut but on the base metal. I generally use a tapered drift or our alignment bar in our kit to align the nut and base metal but thats me.

 

just my .02 in this discussion

[Jim Coke]

Greetings Scrambler, 

        I designed my welding tables years ago with a unique leg leveling system. I used about 10 inches of square tube welded to the top section ( short legs) . The outer legs, square tube with square floor plates I put pinch bolts with handles so I could adjust for uneven surfaces from the top. They have served me well for years., I will try to add a picture later today.. 

Forge on and make beautiful things 

Jim

[Jim Coke]

Greetings Scrambler, 

      The pictures show my leg design. A few other things... Angels welded in the center with flats on the bottom for clamping fixtures and other tools . The removable top plates also have mating angles on the bottom. I have many devices that mate and clamp into the angles for holding and cutting. I made 2 complete benches which clamp together for bigger projects ( railings and big flat stock)   I hope this helps.. Good luck on your build. 

Forge on and make beautiful things 

Jim

[WayneCoeArtistBlacksmith]

And with a Cole Vise on the end of the table.  Thanks Jim for all the information that you have given me about this unique vise and drill system.  I have two set up on two of my tables and I use them daily.  I haven't gotten much use out of the drill but am glad that I have a complete setup.  Between you and Fred at Quad State I have learned a lot over the years.

I miss you, be sure and tell Fred that I miss him too, along with all the other friends that I made up there.

Let me know how I can help you

 

Thank you,

 

Wayne

[TimberBull]

I cleaned the material and clamped the nuts to the top with vise grips.  Tacked and then welded all around the base of the nuts. I then screwed the bolts in and heated with a torch until I could pull them into the angle I wanted. Very sturdy and heavy forge table.