Welding Grade 8 Steel Nuts/Bolts

I am building a watts link for my 51 Chevy and I am going to use Grade 8 hardware on it There are a couple places that I was planning on welding nuts to the center link. Is there anything special that I need to know about welding grade 8?

Thanks!

 

penetration

 

I don't know if it matters or not but I usually grind the coating off and then weld

 

Grade 8 fasteners are made of 4140 type alloy then heat treated. Excellent weld stock although the heat may anneal them some.
And yes, penetration

 

With stick, use 7018 rod.

 

After welding, you'll probably end up with something very different than a grade 8.

 

Very Different as stronger, or trash?

 

Remove The plating before welding.

Craig

 

more than likely wont be as strong as grade 8, you will put so much heat into them the properties will change. will probably do the job though.

 

That much heat will take the temper out, it wont be near as hard.

 

any time i weld a nut to anything, i usually thread the bolt into it so you don't twist it and fuck up the threads!!

 

I haven't done it with grade 8 bolts, but I've done it with the shiney plating on grade 5: Soak the fasteners in regular white wine vinegar for several hours, or over night. It strips the plating off, and leaves a real nice, unshiney, gray surface that takes a weld very nicely.

And yes, welding will change the structure of Grade 8.

-Brad

 

If you weld it with the bolt in it you take the chance of it shrinking enough to damage the threads when you screw it out. Remove coating, use a Qtip to put some antispatter in the threads. Weld and let cool slowly. Run a thread chaser, not a tap, through it and your good to go. It will be softer than original, but not enough to bother. Use a torque spec for grade 5 fastener.

 

You need to find a good welding procedure. There are several sites like the one below. AWS is a good place, also.....slide



http://cr4.globalspec.com/thread/11472/Welding-4140

 

This one is right on the money..... Ive learned this through trial and error

 

Do this.

 

i never knew that! see , just goes to show you do learn something new everyday! one of the many reasons i joined the H.A.M.B. tons of useful knowledge and alot of people who know their shit!! thanks

 

This is how I have been doing it, I've been lucky so far.

 

I suppose you have experience regarding this, but I have done it to hundreds and never had a problem with unscrewing. Done it to # 10's up to 7/16

 

Cool, thank for all the replies.

 

I spray some anti-spatter on a stainless steel bolt, and use the bolt to hold the nut where I want it for welding. Don't have the threads of the bolt stick out past the threads of the nut, or you risk having a blob of weld splatter getting on the threads of the bolt, which can chew up the threads when you unscrew the nut. I use a stainless bolt to hold the nut in place, because the melting temperature of stainless is a little higher than carbon steel.

If I weld a plated nut, I just use a sander to sand off the plating on the six sides of the nut.

What's nicer though is to use un-plated nuts. McMaster-Carr sells them. They're just bare steel with a little oily film on them to keep them from rusting. They also sell un-plated square nuts. Square nuts are easier to weld and have a little more weld area to make a stronger anchor to the plate you're welding them to.