Back box lugs and cross threads.

[Dave OCD]

so you got wet. think anyone cares? i don't .

I wouldn't imagine you work as a Samaritans volunteer Tel ?

 

[westward10]

so you got wet. think anyone cares? i don't .

Why was it raining

 

[sparksburnout]

The M3.5 tap is also useful when plasterers of today fill up the lugs with cr@p, as well as a fair bit of the box. There was a time when they cleaned boxes out really well but that seems a rarity these days.

Blimey you must have had polite spreads down there, I reckon the b****s do it on purpose. I usually coil the cable all the way round the rim of the box, helps a bit. What I hate is when the builder cuts the board too big so you end up with a thin rim of plaster round the box that cracks and looks crap when you do your second fix.

 

[Dave OCD]

Blimey you must have had polite spreads down there, I reckon the b****s do it on purpose. I usually coil the cable all the way round the rim of the box, helps a bit. What I hate is when the builder cuts the board too big so you end up with a thin rim of plaster round the box that cracks and looks crap when you do your second fix.

Me too ! Despite our best efforts we're often at the mercy of idiots.

 

[uksrevivor]

I may be wrong here but the older back boxes had a different thread imperial if im right which when you use the newer faceplates on them the newer faceplates have metric thread screws 3.5mm which are different and can strip the older boxes thread.
I always use the 3.5mm re threading tool on old installation boxes and nearly always have to use it on second fix after the bloody plasterer has filled me boxes with plaster lol

 

[Marvo]

If the damage to the original thread is bad you can drill it out and use a 3mm clinch nut (AKA rivnut) and manually tap it out to 3.5mm after you've inserted it. You get aluminium clinch nuts which are easier to re-tap because they're softer than the usual electro-galve steel variety.

 

[rsgaz]

older back boxes had a different thread imperial if im right

It was 4BA thread (≈3.61mm) so it was slightly larger and had slightly fewer TPI also.

 

[Flanders]

Yes as others have said its a must have tool, Just be careful you dont snap the tap off in the lug
You will find you will use it a lot,.
it does anoy me when someone has just powered in a screw without tapping it out first, then i come along to replace the socket / switch and spend a age trying to unscrew it , untill it breaks off

 

[VoltzElectrical]

so you got wet. think anyone cares? i don't .

No, I took my huge fishing umbrella and sat perched on my tool box with the van radio on lol.

One repair I had to do was supposed to have me remove a double deep backbox from a tiled kitchen wall in a school kitchen for a cooker switch because the lower £.5 had snapped off. It would have been a helluva job to get it out the wall with the cables entering top and bottom so I snipped the snapped screw as close to the fixed lug as possible, then filed it flat smooth, re-drilled it, tapped it, and popped a new socket pin in, jobs a goodun.

 

[westward10]

It was 4BA thread (≈3.61mm) so it was slightly larger and had slightly fewer TPI also.

These must be seriously old, 3.5mm been about for decades (don't know how many though).

 

[davesparks]

These must be seriously old, 3.5mm been about for decades (don't know how many though).

I think they changed at around about the same time that cable sizes changed to metric, as i only ever come across them in installs with imperial cables. I don't the exact date of the change but the 14th edition was reprinted in metric units in 1970 so that should give a rough idea

 

[Barry White]

A couple of my upstairs back boxes were black japaned boxes with 4BA screws fed by slip tube conduit. They are still there somewhere (plastered over) The switches are on the other side of the door now. Unsure whether the hand of the doors was changed after the rewire or before but switches were behind the door.