Drills - question for metalurigst?

The little dodad on the end is more pointey

I'm not 100% sure, but I would guess diamond impregnated metal tip running with very low thrust and lots of coolant. Same basic procedure as glass. You aren't really drilling as much as wearing away a round hole.

Search google for "drilling holes in glass" or something similar.

Regards, Joe Agro, Jr.

No.

Masonry is brittle on a small scale, but not on a big scale. So we don't usually _drill_ it, we chisel through it with a hammer drill. If you look at the edges of a masonry drill bit, they're blunt and have no edges at all.

If you try to hammer-drill glass or ceramics, they'll crack. So you need to use a rotating chisel edge, as we do for wood or metal. Because they're hard materials though, we use the same tungsten carbide inserts as the masonry bits, but they're not ground the same.

Most drilled glass or cermaic is in thin sheets, so there's not much dust or swarf to get rid of. They don't need the spiral flutes to clear the muck. The simplest drill bit is thus a "leaf" bit, a simple oval of carbide, brazed onto a narrow shaft and sharpened with a sharp edge. These are cheap, not too hard to find, and the best way to drill most glassware.

Drill ceramics wet with oil. Make a circular dam around the hole, using glazier's putty (which is made of oil, so it's oil-resistant - Blu-tack will loosen and fall off). Put a shallow puddle of oil inside this dam - almost anything will do. Then drill slowly and with light pressure, "dabbing" the drill up and down to let the dust out. Be _very_ careful when the hold breaks through to the far side.

You really need a drill press to do this. Hand-drilling it will have a lot of breakages.

i drill glass sinks. 1" to 1.5" thick. diamond core drills are fastest, although loose carbide and a piece of copper pipe works too. use lots of water.

a tripod drill with a center water feed tap is best. these are NOT cheap.

Or an ultrasonic mill/drill

Niel.

those look way cool, and a probably more than a few orders magnitude more expensive than a tripod drill.

i suppose a water jet could cut these too, but those are probably out of the price range of a normal user. i use my sandblaster for thin (

Thu, Nov 18, 2004, 1:31pm (EST+5) snipped-for-privacy@aol.com (JMWEBER987) says: The little dodad on the end is more pointey

You really should have dumbed down your response more, not all the people here will know what technical terms like those mean.

JOAT Measure twice, cut once, swear repeatedly.

I thought about it, but didn't want to insult anyones intelligence. Mike in Arkansas

Thanks to all! Got the pic. Off to work.... Max