Drill and Tap chart explained

[@watching4410]

Do what due size do I use?

[@Kpax72]

You should start off by determining the tap size you're trying to aquire and then what drill size is needed.

[@alkennedy1124]

It’s more confusing then ever , why can’t it be easier to find out the drill size for National find a national course threads standards ?? Is there anything to look at for that kinda help ??!! Thanks BigAl California

[@Kpax72]

You need to look up a NC tap chart, this is pretty generic.

[@theobarbosa]

I have a problem; I want to buy a drill and tap for standard sizes for my screws that I have: 1/4, 3/16, 5/32, 1/8, etc... But I only find numbers that I never seen before: 10-24, 6-32, etc. Is this compatible?

[@saginaw60]

See ya gut fraction sizes & algorithm sizes. 10-24 means size 10 wire with 24 pitch thread (24 per inch.) 6-32 is 6 wire size with 32 thread per inch.

[@stownley2005]

What’s the deal about the drill sizes in red? Why even make them in red if there is no direct tap for that size?