Full threaded, slot head pole bolts for humbuckers and P90s.

If you're working with "fresh" bobbins, then the thread size doesn't really matter - as a new bobbin will normally take either an M3 or a 5-40 UNC thread - but its worth considering the thread size if you're working on an existing pickup, where the threads have already been cut into the plastic.

Generally speaking, Pickups made in the USA will use a 5-40 thread (being Imperial, that's their national standard) - everything made in the far east, is likely to be made using an M3 (being Metric counties) - makes sense.

Pickups made everywhere else in the world, could be either - and this is down to the trend for making "historically accurate re-creations" - mimicking what Gibson® did (and still do) - so there is the chance, that a pickup made in a strictly metric country, might be sporting imperial pole screws.

It is, too, a complete pig to measure - but as a rough guide - an M3 bolt will be, roughly, around 2.8mm, where a 5-40 would be just over 3mm.

Now, this doesn't sound a lot, but trying to fit metric bolts into imperial "holes", means they'll just fall out, but, if in doubt, go imperial (It will re-cut the threads in the bobbins, and you'll be fine)

Please Note - these poles will not mesh with DiMarzio® pickups (whilst DiMarzio pickups use the same thread pitch, they're bolts are marginally oversized - nearer 3.3mm - so our 5-40 UNC bolts dont grip (this can be fixed by re-potting the pickup though, the margins are very small)