Bought some stainless steel wheel nuts for the SD1 and the instructions recommended a hex socket - AF, of course. So had a look at my local Halfords - I'd have to go quite a distance for a proper tool shop. All the decent tools are under lock and key, and while looking through the glass an assistant arrived and opened it up. Not a youngster - probably 30+. Of course all they had was metric sockets, but thought I'd try them just in case. 22mm hex for an impact driver was too small and 24mm - the next 'preferred' size - too large.
But the assistant plainly had never heard of anything other than metric sizes, and didn't know the difference between bi-hex, hex and 'sides' drive.
I'll probably just use my AF bi-hex as I'm not going for concours. ;-)