You just need a 2-56 tap mate. What type of material are you going into? If Ti then there are some things to consider as it’s pretty easy to break these little taps.Have some '2-56 X 1/4″ Diameter Short Socket Head Screws' from Ti Connectors.
For the ignorant who are only familiar with metric, what do I use to put a female thread in some metal for these little boy?
Will they just thread them selves if the hole is close to size?
Yep - absolutely. I’d by a couple of taps in 2-56 and you will be fine. I bought a few online that were quite cheap and they have worked well. I broke a few when I first started trying to tap Ti but I have worked out my process now and am pretty confident. If you are tapping annealed high carbon steel you should be fine. Gun nose taps are often quoted as being best style to use but honestly just a normal tap works well for me.THANKYOU. It looks like I need some smaller taps in Imperial sizes.
Buy a hand tapper. Using a taping handle by hand you will break a tap often (2-4holes). I did reasonably well with a portable drill. But a hand tapper is the cure.