Micro screw threads? Less than 4-40?

[ghost_a*]

i'm working on mounting my custom control box as well as bunny ears to my emitter shroud.
as i used to build computers for people, i have a bunch of micro screws used for things like hard drives, motherboards, etc.

i'm not positive the threading size, but i know they're less than 4-40.
i'm assuming 2-56.
these are the perfect size to mount both the bunny ears as well as the control box. i think 4-40 would end up being a tiny bit too large.

i have a couple questions:

1. how would i go about finding the threading size for these?
2. are there places locally that would sell a tap this small? i went to lowe's on my lunch break and it looked like the smallest tap they had was 4-40.
i couldn't find an employee who was free to ask them if they could special order something like this for me. and i didn't have the screw with me to check if they could size it or something?

if i had to eyeball it, it'd be extremely similar to these hex screws VV used on their starkiller:

[acerocket]

screw diameter:
4-40 = .112"
3-48 = .099"
2-56 = .086"
1-72 = .073
0-80 = .060"

I have used almost all of these sized screws at one time or another doing sabers. If I recall, the screws on the VV Starkkiller are 2-56. As far as sourcing a tap, you will not find anything less than 4-40 at Lowes, Home Depot or your local Ace hardware stores. You will need to look for a local industrial supply house and see if they might carry them. More than likely, you will have to order them from some store online.

[ghost_a*]

well ****e...
i thought that might be the answer. all right, thanks for your help.
i bet fastenal has it. i'll check with them.

thanks.

[Xanatos1986]

be careful as those parts are exspensive I bouth 12 2-56 set screws and a alan head wrench and paid over 30 bucks from fasenol. and the tap broke. go me lol.

[FenderBender]

McMaster also carries the taps and the screws.

On our Starkiller, 2-56 was used on the control box, but 4-40 were used on the bunny ears, and side shroud screws.

[ghost_a*]

thx guys, yeah xan, fastenal has a tap for like $7-8
up there in price, but i'll probably go with them since i won't have to pay shipping.

thx fender for the confirmation. i'm gonna end up using 2 2-56 screws for the control box and a 3rd for the bunny ears.
i'm currently running 8-32 for my button head shroud screws, but i'm going to downsize to the 4-40.
i think they look better and give more surface area space for the control box as well.