Drilling holes in granite - Contractor Talk - Professional Construction and Remodeling Forum

zipicus · 09-08-2009, 08:11 PM

Is the only way to drill holes in 3/4" granite slab say a 3/16 hole, is with a hammer drill?? I tried the Bosch Blue Granite to install some grab bars in a shower w/granite walls and it went pretty easy on one install I did awhile back, no hammer action. Then today, again grab bars in granite shower(black granite), the first hole was no prob, 10 min., the other 5 holes took about a half hour each.???

BCConstruction · 09-08-2009, 08:28 PM

Every granite drill system i have ever used has said never to use hammer action. I wouldn't advise it unless there is a tool design that can drill it with hammer without chipping or cracking it. Be the first time i have ever heard of one.

Biff · 09-08-2009, 09:05 PM

The best way is to use a DRB01375 bit made by Alpha. You can use this with an angle grinder or with an adapter that comes with them so that you can use them on a regular drill.

zipicus · 09-09-2009, 09:47 AM

Thanks, the Alpha bit sounds good but $107, Ouch. Well I guess it's better than spending a half hour on each hole w/a Blue Granite bit.

woodchuck2 · 09-09-2009, 03:15 PM

Hammer equals broke IMO.

BCConstruction · 09-09-2009, 03:43 PM

Quote:

Originally Posted by woodchuck2

Hammer equals broke IMO.

Exactly what would happen if i done it. But i wont lie and i have seen a couple of chippys drill granite tile with massive happer drill to get a fixing in a wall and they got away with it. I know for a fact it would crack in half if i dont it. But i have seen the same people crack ceramic tiles many times doing the same thing.

Just not worth the risk.

glassman · 09-11-2009, 09:29 PM

We use mini diamond core drills bits from CRLaurence company, they are available in sizes from 1/8'' to 5'' in diameter.
easy to use in a cordless drill just use a spray bottle to apply water to cool bit as you drill. They were developed for the glass industry and have crossed over to stone,granite,marble,etc.
time to drill a 1/4 hole in black granite about 20 seconds

Jayrek · 09-12-2009, 02:35 PM

Quote:

Originally Posted by woodchuck2

Hammer equals broke IMO.

Yep. Hammering (drill) granite will increase the chance of cracking it. Unless you are quarrying it dont try it. High speed diamond w/ plenty of coolant will suffice.

WilsonRMDL · 09-12-2009, 09:57 PM

When i was installing granite for a living we used coring bits, always used a metabo grinder no hammer drill.