Clearance Drill For 10-32

[rwm]

I use a lot of 10-32 screws. The diameter of this size screw is published as 0.190 nominally, Although some seem smaller. Based on this nominal diameter they will not fit through a 3/16 (0.188) hole. What diameter do you use to drill clearance holes for these? Is there a metric size that works well? Any other ideas?
R

 

[Billh50]

Here's a link to standards for tap drill and clearance

http://www.engineershandbook.com/Tables/taphole.htm

 

[JR49]

rwm, You might want to check your 3/16 bit, to make sure it is not undersize. Just yesterday, I drilled a bunch of 3/16" holes and the 10-32 screws fit fine. (I'm assuming that 0.0188 is a typo, should be 0.188) Good luck, JR49

 

[rwm]

Fixed the typo. Drills are fine. Some #10's are undersize and do fit nicely in a 3/16 hole. If they are to spec, they shouldn't fit.
R

oops another typo: #10 should be 0.190.
R

 

[rwm]

Here's a link to standards for tap drill and clearance

http://www.engineershandbook.com/Tables/taphole.htm

Thanks Bill! I should have looked there.
So I need to get a #9 drill for a tight fit clearance. Seems I could also use a 5mm drill and be very close.
R

 

[Billh50]

No problem...always willing to help

 

[Wreck™Wreck]

The number X .13 + .06 = the major diameter.

 

[randyc]

The number X .13 + .06 = the major diameter.

I think there is a typo, shouldn't ".13" actually be ".013" ? Pretty cool expression, I've never heard of it before

 

[machinistmarty]

I was modifying my vise stop just today. Went from set screws and a slotted hole to thumbscrews and split cotters.(Man is it so much easier to use and more convenient) Anyway, a no. 9 drill is what i used for clearance. I didn't have a chart, my index has the # size as well as the decimal equivalent. Tomorrow i will try to finish the rest of it and take a pic.

 

[Andre]

Most drill indexes have a tap drill chart stamped in them or printed on the inside of the lid.