Pilot Hole Tolerances for Wood to Not Split.


Junior Member
Hello once again,

As I'm soon to be drilling multiple holes into my body and neck for various screws I have measured the screw shaft widths, and the hole depth (With the part attached to account for part thickness and not over tighten into the wood to split it).

My question here is, I have a few screws measuring 1.7mm and 1.3mm, and a few others in the -.0mm and -.5mm range, I know my calipers to measure aren't perfect for the job so the .7 and .3mm screws may be a touch smaller in size so can I use a slightly smaller drill bit here and make the pilot hole without worrying about splitting wood? Or is this a job where the hole needs to be 100% exactly the size of the screw shaft so the slightly larger shaft doesn't split wood?

They're not huge screws, but I don't want to risk it my first time out without some advice...
For me, I eyeball it.  How does the drill bit look when you hold it over the screw.  The more screwing you do, the better you get at it.  If you're not confident, try screwing some scrap wood and see what happens.

I recommend you do a search for the Aaron's video on his two neck build.  You'll get tips on using tape to protect the paint etc.  Good luck screwing!
I use a 5/64" straight bit for the tuner screws (#3 x 3/8"), string retainer scews (#3 x 3/8), and pickguard screws (#4 x 1/2").

Some charts say 5/64" and some say 1/16" for #3 screws, but this is the one I turn to most. Alder, ash, maple, etc. is hardwood. Basswood and pine is soft. Hardwood will crack under pressure so it uses the larger pilot hole, soft wood will give more and needs more material to not strip out.

Even though I have a drill press, I only use it when necessarily, instead I tape the part in place and use a self-centering hinge bit taped off for the right depth.
You basically want no thread in air, and no shaft in wood