Precise fully hardened chrome vanadium steel for driving socket screws.

Why not buy a coloured canvas zipper bag to keep them handy?

If you are working on stage the two sizes you really ought to have in your toolbag, or your handbag, are the 1/4” and the 8 mm which will fit the popular key clamp tube fittings for size 6 and size 8
scaffolding respectively. This 6 mm key will fit the size 6 scaffolding clamps, but it is a sloppy fit!