Nuts Bolts and Spacers -Sorted thankyou

Very simple questions.
What tread size?
What height spacers do people recommend to clear ports etc when stacking on GPIO headers.

Pi is a Pi Zero

I believe those are M2.5… I think I use 5mm spacers (just for the back legs) with the Zero enclosed in one of our case.

I haven’t really stacked multiple pHATs (or at least for a permanent setup so haven’t bothered with spacers) though at a glance I’d say 5mm is not enough for the interspace… maybe 8mm (5+3)?

… sorry to be vague, have now left for vacation and haven’t got my arsenal of nuts and bolts at hand to be more precise.

I use a number of boards with my various Pi 3 projects and the standard for me is m2.5x10x6. Relay boards can sometimes be a bit tall and m2.5x15x6 fills the bill.

“squiregeek” thank you for your reply, will now sort out ordering all the necessary bits and pieces.