Weld nut replacement

[Classic Car]

Hello,

My first post here.

I'm currently repairing one of the seats in my classic car because the hinge has come loose due to a broken welded nut inside the metal frame.

Luckily I have found a new replacement weld nut from this place: (see link below)
https://www.accu.co.uk/en/weld-nuts/495 ... N-M8-8-8-Z

I have dismantled the seat (removed upholstering and foam) right down to the seat metal frame but how do I install this new nut? Will a plumber's blowtorch (like Mapp gas) work?

Thanks

[Rorschach]

No, you will need a proper welder.

[Classic Car]

Thanks but this type of nut already have six small projections added around the edge.

Doesn't it mean those 'projections' only need to be melted to make a weld?

[Dave54]

Must say I didn't know anything about weld nuts, apart from having heard of them vaguely.
There's a bit here.
https://en.wikipedia.org/wiki/Weld_nut
Looks to me that type is meant to be spot welded on, and the boss is for location.
So I'd say your alternatives are either to find someone with a spot welder, assuming you can get access to it for that or to just weld it in with MIG or whatever.
You won't get enough heat with single gas blowlamp type torches. I looked into it a bit back.

[Bob225]

Thanks but this type of nut already have six small projections added around the edge.

Doesn't it mean those 'projections' only need to be melted to make a weld?

In a word NO you need to weld it on with a welder, a local garage or machine shop/fabricators will weld a nut on it for not a lot of money if not free (its appreciated

Its no different to a normal nut its just got a collar*, the image is just a poorly drawn its just chamfered on the points

Where are you located ?

Edit. you want a steel nut the one in you link is stainless steel

[arco_iris]

It isn't actually necessary to purchase a proper weld nut at great expense & postage, any steel nut will do. Weld nuts were used in the factory for speed of manufacture.

You hold the plain nut in place by threading a bolt in from the other side, if necessary using washers or spacers, then just tack weld the nut in place. When cool, extract the bolt and the nut stays behind.

As has been said, virtually any small motor engineer, or steel fabricator, will put a blob of weld on for a tin of biscuits.

Anyway, could you not just reassemble the hinge with the original bolt (I expect it has a shoulder on it?) & self-locking nut, without resorting to welding?

[Classic Car]

Its no different to a normal nut its just got a collar*, the image is just a poorly drawn its just chamfered on the points

Where are you located ?

Edit. you want a steel nut the one in you link is stainless steel

Description from the website:

What Are Weld Nuts?

AccuScrews’ Hexagon Weld Nuts are designed to be welded to a target housing, creating a robust and hard-wearing fastening after installation. These components feature six small projections around the edge of the nut, which help to improve the strength and uniformity of a weld.

I'm located in Sheffield.

Yes, I'll be getting steel, not stainless. Thanks.

[Classic Car]

Must say I didn't know anything about weld nuts, apart from having heard of them vaguely.
There's a bit here.
https://en.wikipedia.org/wiki/Weld_nut
Looks to me that type is meant to be spot welded on, and the boss is for location.
So I'd say your alternatives are either to find someone with a spot welder, assuming you can get access to it for that or to just weld it in with MIG or whatever.
You won't get enough heat with single gas blowlamp type torches. I looked into it a bit back.

Thanks for this.

[Classic Car]

It isn't actually necessary to purchase a proper weld nut at great expense & postage, any steel nut will do. Weld nuts were used in the factory for speed of manufacture.

You hold the plain nut in place by threading a bolt in from the other side, if necessary using washers or spacers, then just tack weld the nut in place. When cool, extract the bolt and the nut stays behind.

As has been said, virtually any small motor engineer, or steel fabricator, will put a blob of weld on for a tin of biscuits.

Anyway, could you not just reassemble the hinge with the original bolt (I expect it has a shoulder on it?) & self-locking nut, without resorting to welding?

The seat metal frame already has a specially sized hole for the boss of the weld nut to go into, so I'll be getting that.
Self-locking nut won't work as it's not accessible once the seat has been reupholstered.

Thanks for tip on tin of biscuits. I'll do that if I find someone to do the welding for me.

[Bob225]

The points are to lift the nut off the surface to allow a thick bead of weld (better penetration), as above use a standard nut and bolt and weld up the nut, remove the bolt

There are a few types of these nuts but nothing a fabricator or diy machinist can't knock up

[arco_iris]

Point taken, but properly fitted you won't need to get to the nut once reupolstered.

Thanks for tip on tin of biscuits.

Blokes who can weld have no idea how much a tin of biscuits costs (£3) and it will last them a week of tea breaks. Much better than handing over a few paltry pound coins, anything less than a brown note looks miserly. And the tin is useful after!

Another good one is to stock up on those big tins of roseherobrations in the supermarkets at Christmas, they've all got wives & kids - (but not biscuits with snow scenes on the tin!)

BTW,

[Classic Car]

[Grumps]

Point taken, but properly fitted you won't need to get to the nut once reupolstered.

Blokes who can weld have no idea how much a tin of biscuits costs (£3) and it will last them a week of tea breaks. Much better than handing over a few paltry pound coins, anything less than a brown note looks miserly. And the tin is useful after!

Another good one is to stock up on those big tins of roseherobrations in the supermarkets at Christmas, they've all got wives & kids - (but not biscuits with snow scenes on the tin!)

BTW,

We prefer doughnuts. Even if they are 'short dated'.

For things like this it is always useful to get to know your local Heritage Railway. Volunteers that are not under time constraints, and with the hope that you may become a future 'customer'. From Sheffield, you've got the Elscar Heritage Railway, and if you have a few days a year to contribute, then you may get to learn the basics of welding.

Not that I do welding. I tend to be mainly involved with pipe fitting, as in, [up to] 2" steel pipes for Vacuum brakes and Steam heating.