The stringy thing!

[jeff the gasman]

hi sparks
With five core flex there’s another strand which Is either pvc or thread.
What’s it for?
I’m sure at least one of you can settle a debate. Thanks given for best answer.x
Ps
Sparks are crap at wiring heating controls.x

 

[EFLImpudence]

It's to confuse plumbers.

 

[sparkwright]

I assumed it is a spacer to make the cores sit nicely.

PS, heating engineers are crap at terminating wires properly.

 

[sparkwright]

PPS, a bit of professional rivalry there.

 

[charliegolf]

Stripping back the sheathing maybe?

 

[pbryd]

CAT5e has a thread helping to strip back the sheathing.

 

[sparkymarka]

Rip cord

 

[jeff the gasman]

I assumed it is a spacer to make the cores sit nicely.

PS, heating engineers are crap at terminating wires properly.

CAT5e has a thread helping to strip back the sheathing.

That’s what we thought but the stretchy one?

I assumed it is a spacer to make the cores sit nicely.

PS, heating engineers are crap at terminating wires properly.

its not important and earths get in our way so we fook em off.

 

[sparkwright]

A clear lack of understanding from a bunch of childish plumbers and alarm fitters.

 

[jeff the gasman]

A clear lack of understanding from a bunch of childish plumbers and alarm fitters.

Relax mate.

 

[sparkwright]

I'm just having a joke, don't mind me.

 

[securespark]

CAT5e has a thread helping to strip back the sheathing.

So does telecomms cable, but I don't think the one in the flex is made of the right stuff for stripping.

 

[JohnD]

It's to confuse plumbers.

Shooting fish in a barrel.

Seems a bit unsporting.

 

[stem]

It's to help reduce tension in the centre of the flex and to stop the cores deforming inside the sheath. As the flex...erm... flexes. It reduces the amount that the cores compress inside the bend or stretch on the outside of it. So in a nutshell, as @sparkwright said:

I assumed it is a spacer to make the cores sit nicely.

 

[SUNRAY]

It's called a 'Filler' and it's job is to fill the gap.
2,3,4,7 core don't need it as the wires lay together nicely.

It was used in some of these cable sizes many moons back when it was easier to create a tube for the outer sheath but not needed now with the way the sheath is moulded to the wires.

Also there may be a thin (fairly fragile) thread or three used to identify the batch or year or something.