Tool Time: Drill Bit Sizes

I often need to use a micro drill bit set like the one shown below. The main thing I use it for is to open the holes in pearls a little bit. Pearls have such tiny holes, and sometimes even a 24 gauge headpin will not go through. By starting with the smallest bit in a micro drill bit set, I can gradually work my way up to a larger size bit and enlarge the hole very easily.

The drill bit sets such as this and the 20 piece replacement set have confusing numbers - the 12 drill bits in the set are sizes “52 - 74″. Some sets say, “.0635 - 0225.”   But what does that mean to you?

There is a very handy website at http://bobmay.astronomy.net/misc/drillchart.htm

This is a drill bit size chart - and it will tell you in millimeters, inches, and the number designation, as well as a few suggestions as to how to use different drill bit sizes. I have found this extremely useful!