Quite a specific screw to be honest - i cant think I've seen them being
used for anything else apart from mounting Filtertron pickups.

Full Thread, slot head bolts used to mount a humbucker through the pickguard or mounting ring.
Available in Nickel, Gold and Black, 33mm thread lengths

A slightly strange screw in the grand scheme of things - most definitely
a #4 screw based on its thread, but with a #2 sized head.

Full Thread, Phillips, Round head bolts used to mount a humbucker through the pickguard or mounting ring.

(2)

Set of 8 3/4 Thread, Phillips, Pan head Screws designed to screw into a guitar body/nut and hold a Bass pickup or P90 against its supporting springs/Foam. Available in Nickel, Black or Gold.

A twist on a common these with these "small guitar screws" - #2 countersunk screws!

If I was to be VERY strict about this, I've only ever seen these turn up on guitars in places i would expect to see #3 screws - almost entirely cross compatible (thread diameter is 2.2mm rather then 2.4mm) but, importantly, the heads are slightly smaller on the #2s vs. the #3s. (2.4mm vs 2.8mm)

"In House", we call these screws PSH's, but to give them their real name, they're #3 Countersunk screws! They're, in very simple terms, the "truly countersunk" version of our All Purpose screws, giving a slightly cleaner finish, (assuming) your recess is for a #3 screw head.

We’ve called these screws “All Purpose” for so long now,
that I’ve actually struggled to get my head around the idea of calling them by
their “real” name - #3 x ¾”, Oval head screws!

This is a set of switch mounting and pickup height adjustment bolts for the Fender® Statocaster® and similar guitars.

Specifically, these are 6-32 UNC (imperial thread) bolts, with dome, phillips heads, with 6 "small" head screws for the pickups, and 2 larger headed versions for the switch, as well as 6 height adjustment springs.

(1)

This is a set of switch mounting and pickup height adjustment bolts for the Fender® Statocaster® and similar guitars.

Specifically, these are 6-32 UNC (imperial thread) bolts, with dome, phillips heads, with 6 "small" head screws for the pickups, and 2 larger headed versions for the switch, as well as 6 height adjustment springs.

Full Thread, Phillips, Dome head Screws used to mount a humbucker through the pickguard or mounting ring. Supplied with Springs (4)

(1)

Height adjustment sponge for a dog ear P90 - not something that actually turns up all that often on guitars "from the factory" - but a handy little option to get dog ears actually working for you - supplied with an adhesive backing, and made of neoprene sponge - simply stick them under the pickup, and screw it back down onto the body.

Quite a specific screw to be honest - i cant think I've seen them being
used for anything else apart from mounting Filtertron pickups.

#3 Round head Screw

Mount screw used to fix the base plate to a P90 bobbin, the base plate to single coils and Telecaster pickups, and various other jobs on the guitar.

These are the very small screws which you'll see mounting truss rod covers in place on the headstock

When we're dealing with surface mounting pickups, traditionally, there will be some relatively hard, close celled foam underneath which will give some level of height adjustment - its certainly not variable as "hanging" pickups, with the bolts and springs, but its fairly common - The Jazzmaster®, Jaguar®, Precision® and Jazz® Bass, as well as most P90s will employ sponges.

6-32 UNC bolts usually turn up on American/Mexican/UK made instruments and parts - primarily pickups and switches, but they are becoming more common on Eastern made things too nowadays - its a little bit confusing, because theres a few different "types" (and you do get guitars that have a mix of different heads/lengths) - so as a quick, rough and ready guide.