Drill sizes?

[Alex]

On many drawings the hole sizes are shown with a number (#). What does it stand for? Is a conversion chart used to find the diameter?

 

[ed miles]

Drills come in four basic size groups. Fractions, Letters, Numde and Metric. Are your drawings Imperial or metric. If they are Imperial system you would be using number drills and if it is Metric you need metric drills. Your best source for decimal equivalent sizing would be a Machinery Hand Book or you local supply house usually has conversion table wall charts and pocket charts.

Ed

 

[Alex]

I made a search on Google and found quite a few charts.

Here's one: www.saw-online.com/Tips/drill.htm

 

[ed miles]

Alex, that is a good all in one chart for you shop wall, or tool box. Print it off, a couple of copies are in order so you can always find one of them.

Ed

 

[loggerhogger]

A lot of tool stores sell drill bit sets that have letter, number, and fractional sizes all in one set. Very handy. and not too expensive.