Following on from my enquiry about small head Hex bolts, I needed a 9Ba box spanner (Nut runner actually). Sorting through the come in handy metal stock box, I found a snapped off telescopic car ariel. One of the sections was about the right size to make a small box spanner. I took an old hex key and ground it such that it would enter the tube. I 'drifted' it into the tube to form the right size hex, then sawed the tube off to length. Cross drilled for a tommy bar and silver soldered it into place. Magic. Perhaps not the strongest, but suits my purpose. I suppose I could get the next sized section tube, slide it over the hex portion and silver solder into place etc.etc