I am sure there are many times when you know the spanner or socket size for a bolt but have picked up the wrong size.

You may also be aware of a Draper spanner and socket sets that are colour coded for size.

Rahter than spend cash on more spanners/sockets, the low-cost solution is to use insulation tape.

Using the resistor colour scheme, my spanners and sockets are size coded.
e.g. black = 0, so 10 mm or 20 mm
red = 2, so 12 mm
green = 5, 15 mm

And ofr imperial used yellow for 1/2 in.

[img][/img]

Wish I had that much spare wall space!

I tend to buy spanners and soockets with the sizes stamped on the side, a quick glance will tell you have the right size

Makes it easier than trying to remember what colour means what size.

But I do like your Locost solution

but once you've got red / yellow = 13mm it will be damned easy to find that spanner on the floor instead of picking every one up twice until you find the one you miss the first time round (as i normally do)