Nut for a speaker cable socket

[DF Shortscale]

Probably a simple question here, a nut fell off one of my speaker cable ports in transit so I need a replacement, does anyone know if these are just 6.35mm socket nuts? (Like these). 

If so, do any high street shops sell these? I can order one online but it costs 11p, with £3.99 shipping which seems silly so if I could get hold of one locally it would be better.

 

[shybaldbuddhist]

I needed one of these last year but couldn't find anyone selling them locally. Shops said they're not worth stocking as they're so cheap and demand is very low. I ended up getting one from All Parts for 50p plus £3 postage.