Stripped thread ..

[RogerS]

...in a pattress. For a light switch and I've managed to strip one of the lugs. Removing the pattress is not an option. Scratching my head, this end. I nadgered it as I thought it was M4. Mmm...wonder if an M4 will go through the front plate and do I have one long enough

 

[jimhanna]

Screwfix(and other suppliers) sell a tool to rethread damaged sockets.

 

[jimhanna]

Just to add to the above, if your box is old it may have a thread which is smaller than M3.5.
I found I had to buy M3.5 screws as well but apart from that the tool worked well, stopped me having to
remove the whole box.

 

[spb]

As Jim mentioned, the standard thread for electrical accessories is M3.5. An M4 screw will fit through the holes in most faceplates, and if the lug is knackered beyond the ability of the tool above to re-thread, then tapping it as M4 and using one of those is often a viable fix. There are also exorbitantly expensive products on the market to rescue a lug which is completely gone, and some other nuclear options which will work (and not technically break the wiring regulations) but also have some future electrician think "who the hell did this?". I'll save those for if re-tapping in either size doesn't pan out.

So, first thing I'd try is re-tapping at M3.5 using that tool. If that doesn't work, tap it to M4 and try that. If neither works and you don't fancy spending silly money, report back and it's time to get creative.

 

[RogerS]

Screwfix(and other suppliers) sell a tool to rethread damaged sockets.


View attachment 29140

Too late for that. I tried but used the wrong sized tap...M4...

 

[Robert]

Crush the lug with a mole wrench. It might buckle or it might just squidge the hole oval. Either way you should be able to cut enough of the right size thread for a screw to hold.

 

[Lurker]

Would a socket extension screw help?

2x Socket Extension Screws Switch Box Screw Extension Studs 3.5mm Terminal | eBay UK

2x Socket extension screws.

www.ebay.co.uk

Put a nut behind the lug.

 

[AndyP]

Put a nut behind the lug.

I was thinking that too, but how would you stop it spinning, glue it place perhaps

 

[Lons]

There are a few things you could do. I'd try coating front and back and filling the hole with JB Weld or epoxy then drilling and tapping again. Both those accept a tap well if you're careful. Solder can work in a similar way. You could also (carefully as it's brittle), enlarge the hole in the socket face and use a larger machine screw or even a self tapper. Use one of those slide over captive nut thingies the use on cars then a self tapper or even widen the hole a little more and shove in a plastic wall plug.
All botch jobs of course. I'd replace the box but I realise that would be an issue at the minute.

 

[spb]

You could also (carefully as it's brittle), enlarge the hole in the socket face and use a larger machine screw or even a self tapper.

You often don't need to enlarge the faceplate holes for an M4 screw.

 

[Lurker]

I was thinking that too, but how would you stop it spinning, glue it place perhaps

I meant nut the socket extension to the lug.

 

[AndyP]

U nuts?

40 Spring Type U Nut 3mm Screw Size Zinc & Yellow Plated Metal Clip 18mm x 12mm | eBay

<li> Spring Type U Nut 3mm Screw Size Zinc & Yellow Plated Length: 18mm Width: 12mm Universal Fit</li> <li> Brand Woodzdon Manufacturer Part Number Does not apply Interchange Part Number Does not apply Reference OE/OEM Number Does not apply Superseded Part Number Does not apply UPC Does not...

www.ebay.co.uk

Shame if you have to buy so many though

 

[RogerS]

All sorted thanks guys. Kudos to who nudged my brain into simply getting a countersunk M4 screw