Stephen wrote:

I measured it with a vernier calliper and I think it was 28.5mm, which
seems an awkward size. Rounding that up to 29mm, I could not find any
29mm spanners anywhere. Would a 30mm spanner be too big or do you
"cheat" and use adjustable ones?

I always end up with Stilsons when plumbing - usually two pairs. I've
always wanted some 'proper' spanners and keep meaning to make a list of
sizes to take to a car boot - I suspect a lot of the sizes required are
imperial/Whitworth ones.

--
Scott

Where are we going and why am I in this handbasket?