HERE
I buy the Drill bit and matching wire sets linked above (link is to a
UK supplier, but they are from P3 which I think is part of Privateer Press, so should be pretty easily available.
Anyway, for £3, you get 2 or 3 bits and plenty of wire to pin with. I used to use a 1.5mm bit and paperclips to pin with, but always had to pack out the drill holes with green stuff - using wire and bits that are matched is MUCH nicer and quicker. I use the 0.85mm bit for most of my metal figures, but I also have a 0.5mm bit, but that does feel a lot more flimsy and I'll only use it on very fragile bits
tbh.