#4 screw

[airman00]

I need to make a hole on a CAD

What size diameter does a #4 machine screw go through?   Would 3/8" be good?

P.S. I cannot test it out tonight and so I need an answer today

[JonHylands]

A #4-40 machine screw goes through a 1/8" hole without touching the sides. 7/64 makes a much tighter fit, but hard to slide in and out. I usually drill my #4-40 clearance holes to 1/8".

If you want to drill a hole to tap for #4-40, you need to drill a hole using a #43 drill bit, which is roughly 0.089".

- Jon

[SomeSaba]

does anyone have a site that has a chart for all these?

They come in handy.. and i can never find them online

[JonHylands]

http://www.americanfastener.com/technical/tap_and_drill_size_chart.asp

- Jon

[airman00]

Thanks guys,
 i got this equation to convert # into inches


Diameter = ( # x .013") + .06" 
So a #4 screw would be .58" in diameter

[JonHylands]

Your equation is probably correct, but your math is way off.

(4 * 0.013") + 0.06" = 0.112"

- Jon

[airman00]

Your equation is probably correct, but your math is way off.

(4 * 0.013") + 0.06" = 0.112"

- Jon

lol  , i realized that !    I was about to go back and correct the post, since I realized a .58" diameter screw is pretty thick, way too think for a #4/

anyway I used a 5/32" bit

[JonHylands]

5/32" will be way too big - your screw will wobble like crazy.

5/32" = 0.156"

I typically use 1/8", which is 0.125"...

- Jon

[airman00]

thanks jon   

1/8 it is !   

i think i'm going to go to sleep now, i had no sleep in the past 24 hours