mikek, if you have a boxed set of wire gauge drills, the box should have eaxh drill marked for gauge size (#1-#60 most common) and the decimal equivalent. If you don't have the decimal, but can determine the # of the drill, either google it or post back and I'll, or one of the other guys, will look it up for you. A small thread pitch gauge can be bought off the internet or at a tool store for a few bucks.

DDA