Pin and weld metric?

[NobullSKS]

I googled pin and weld to see what folks were doing. I only assumed…. Not hard but still.

I considered and option for brazing or high heat silver solder. Since I use it in my trade often. It can be undone with heat….. but threaded parts will never be the same. I guess the amount of heat needed to braze wouldn't be ideal for the barrel…. Let alone if you have an aluminum device.

So how do the inspect these….. just look for a little bead on top? Or does someone wrench on these to be sure? X-rays?

Wouldn't modern epoxy do the trick? I couldn't be the first person to ponder a faux pin and weld. Not that I would do that….. have never had the need. Just conversation purposes.

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[powermad]

Just zap it with a wire feed, not worth the hassle if they do start looking at it.
Cranking on it with a wrench when pinned stands a good chance of trashing it.

I have one that needs the pin popped out, shouldn't be to hard to undo without mangling the whole thing.
It will get replaced so I'm not concerned if it gets chowed a bit.

I'll use a BCM A2x with acuwashers when it goes back together.
I can poke a few holes in the old one and use it to dial in the welder.

 

[Ura-Ki]

I have never EVER has anyone do an inspection, I suspect they would only look IF you were to use said rifle for defense that you would draw scrutiny. That being said, I know your required to both Drill for a pin, and then weld the barrel extension onto the barrel fully, but how they do the inspection, I do not know!
Mine I TIG'ed on, no pin, no drilling, no nuffin, TIG dosn't put nearly the heat into the barrel or devise that MIG will, let alone Silver Souldering with a torch, so,.........
If your that worried, I would take it to a good Smith and have it done to spec, and call it good!

 

[TTSX]

You're over thinking this. There are holes already drilled in a lot of muzzle devices and pins readily available in those sizes. A quick bzzt with any welder in anyone's garage over the pin hole once pin is installed will do the trick. Only has to be solid enough to keep the pin from falling out, doesn't have to hold armor plating on a tank together

 

[hongkong2]

I was always under the impression that pin and weld meant the device was pinned to the barrel then a spot weld to prevent the pin from coming out. Can someone post the cite that requires the device to also be welded to the barrel.

 

[VinnieBoomBah]

I was always under the impression that pin and weld meant the device was pinned to the barrel then a spot weld to prevent the pin from coming out. Can someone post the cite that requires the device to also be welded to the barrel.

A pin isn't required, it's an alternative method to welding the muzzle devise to the barrel

Page 5 and a couple other pages as well

Permanent methods of attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver soldering, or blind pinning with the pin head welded over.

https://www.atf.gov/resource-center/docs/atf-p-5320-8pdf-0/download

 

[hongkong2]

I read this "I know your required to both Drill for a pin, and then weld the barrel extension onto the barrel fully" in post #3 and never heard of having to do both in order to be in compliance.

 

[VinnieBoomBah]

I read this "I know your required to both Drill for a pin, and then weld the barrel extension onto the barrel fully" in post #3 and never heard of having to do both in order to be in compliance.

That's because you don't

 

[Pepe-lepew]

Pin and welding is the most easily reversible since the tack weld can be easily removed and pin pulled. It also does not cause any significant irreversible damage to the barrel.

Tig welding is ideal for welding the pin as it inputs less heat, is much more controllable and has no spatter. If done right, the weld is nearly flush and only slightly larger than the pin.