Wiring this socket

[Ragnar_AT]

Is it just me or do those cables the op is trying to get into his new socket look like 4mm

They do look quite big for 2.5. Maybe they‘re 7/.029? That‘s 2.9 mm2 and stranded conductors have a larger OD than solid ones because there‘s always a bit of an air gap between the round strands.

 

[ebee]

Personally, I never twist solid cables (one strand such as in 2.5 T & E) butb I double them, so 2 x 2.5 doubled on a ring and the spur I might do the single (decent terminals accept 3 x 2.5s doubled anyway).
Stranded (such as 4mm I lightly twist each conductor to keep it aligned with all of its own strands then I might double one or more such conductors.
The target being, so far as possible, to (ideally in theory) fill the terminal hole with conductor to provide a bigger area of conductors contacting. Also helps prevent them sliding into the void between screw end and terminal arc . Cage clamps I am not a fan of.

 

[Adam_151]

They do look quite big for 2.5. Maybe they‘re 7/.029? That‘s 2.9 mm2 and stranded conductors have a larger OD than solid ones because there‘s always a bit of an air gap between the round strands.

That was my first thought, but the earth appears to be single stranded, whereas 7/029 would have a 3/036.

You could order 2.5mm twin as stranded*, which still (at least in teh version I saw) had a solid earth, but like you say, it looks bigger than 2.5mm in the picture, so assuming 4mm

*It was used on a lot of public sector buildings around here in the 90's, when twin and earth in that setting started to become more commonplace/acceptable, but drops were in conduit and they cared about ease of drawing in, don't think you see it much these days

 

[SUNRAY]

Is it just me or do those cables the op is trying to get into his new socket look like 4mm

Yes I believe that is the case

They do look quite big for 2.5. Maybe they‘re 7/.029? That‘s 2.9 mm2 and stranded conductors have a larger OD than solid ones because there‘s always a bit of an air gap between the round strands.

It's a little difficult in pics like these but I believe it looks more like 4mm².

Possibly one of those people who think it's easier and cheaper to run 4mm² radials installed it.

In all honesty

the overall diameter of the bunch of conductors, 4mm² will be ~2.8mm and 6mm² ~ 3.2mm
the diameter of insulation, 4mm² will be ~4.5mm and 6mm² ~5mm
the drill size for tapping a m3.5 thread in the fixing lug hole is 2.8mm
comparing those dimensions the cable could easily be 6mm² or 7/0.029 or even 7/0.036" (but that's pushing it) which was popular in council houses for 30A ring circuits.
Green sleeving sort of indicates imperial cable, as does the silver coloured plating, seeing more of the earth wire and whether it's stranded would help.

EDIT: Apologies for repeated info, I started writing this reply at lunchtime before a visitor arrived and didn't check for further replies.

 

[Paul17088071]

Thanks for your help everyone. I fitted some new sockets which had larger terminals

 

[SUNRAY]

Thanks for your help everyone. I fitted some new sockets which had larger terminals

Thanks for the feedback and conclusion