[dbryant]

Hi, all,

I am going to be trying my hand at drilling some quite small (about 0.5 mm) holes in glass (sorry to post in the metalworking section, but it seemed the most appropriate of my choices). In addition to the size making things tricky, I also have to deal with drilling into a surface that is at a 45 degree angle to the bottom of my drill bit. I could really use some advice on how to do this so that I get a clean hole, and the angled surface doesn't get all chipped (it has a mirror coating on it). Thanks so much!

[tmcallister74]

Do you have a Diamond Core Drill bit? That's going to be the first thing you need.

[txcncman]

I am betting you will have to spot the area with the same size carbide end mill at the same angle before drilling.

[judleroy]

Spotting glass with a carbide endmill is probably not a good idea.
Judleroy

[txcncman]

Spotting glass with a carbide endmill is probably not a good idea.
Judleroy

How do you propose to keep the tiny drill from deflecting off the glass and snapping?

[Andre' B]

I am guessing you will be looking at stuff like this.
Abrasive Technology
Note the grinding burr on the right hand side.

[keebler303]

It seems like their site is down right now but we use bits from Diamond Sure. www.diamondsure.com

Here is someone who sells them: Diamond Sure Drill Bits

Smallest I have used is 3.3mm, not sure how small they make them. Assuming it the piece of glass and the tool are held rigidly (ideally in a mill but a decent drill press would work too) it should be no problem to cut a hole on an angled surface. What you are really doing here is grinding so you want to go real slow and use plenty of water to keep the bit cool. I find it works best to "peck" drill to continually let more water down onto the actual cutting surface of the bit, otherwise it gets dry and then gets hot.

Matt

Thes guys make them down to 0.001" diameter!!
http://www.ukam.com/core_drills_glass.htm