Just dug out the tap & die set and was giving a quick check over. It was a cheap set that got picked up in a hurry for a single use, but thankfully it has the M10x1.5 I need. The tap seems in reasonable condition but the die has fairly cruddy burr on the sides - in fact the cutting edges seem a little rough too. At this point I'm not interested in the die as I'll be buying in the bolts, but it did make me think about building up a replacement set.

I gather the best way to get quality taps & dies on a hobby budget is to get them individually as you need them (thereby spreading out the cost). Can anyone recommend a brand to get (or avoid)? For now I'm only interested in tapping the aluminium for the frame, would the advice differ based on the material?