Drilling in granite

[Brian Knuckles]

I am trying to drill through granite...can anyone tell me what is the best to use.

thx

[Harvey Ghesser]

Brian,

A hammer drill and a carbide tipped bit should drill granite like a hot knife through butter.

Harv

[Tom Bull]

You will need good, sharp bit and it needs to be made for hammer drill use. The hammer drill is essential unless you have a lot of time and patience. Being a natural product it will vary on how hard it is to drill. I have not learned how to drill like a hot knife through butter more like slow, but sure. Don't overheat your bit.

[Dave Russell Smith]

You will need good, sharp bit and it needs to be made for hammer drill use. The hammer drill is essential unless you have a lot of time and patience. Being a natural product it will vary on how hard it is to drill. I have not learned how to drill like a hot knife through butter more like slow, but sure. Don't overheat your bit.
And make sure the piece you are drilling is on a nice flat surface ie plywood

[Dave Lock]

Hi,

If it's a hole in a Granite tile I wouldn't use that hammer drill as there's a good chance it will crack, particularly if it's near the edge.

I use the drill bits that are made to drill holes in glass like these http://teakdoor.com/Gallery/albums/userpics/10332/TILE--GLASS-DRILL-BIT.gif

Not too fast, even pressure and as Dave said, a good backing board to pass into.


Regards

Dave.

[James Stokes]

They make a diamond core bit, I would use one of those.

[Frank Corker]

It took me four drill bits to do five holes, not good odds, certainly not like hot butter. Sorry I attempted it to be honest.

[Stephen Kane]

Here is a source for diamond coated core drills.

http://www.thk.hk/products.php?cid=1

Use plenty of coolant (water) when drilling.

Stephen

[Tim Bateson]

I agree - Slow,Water,Hammer Drill,Masonary Bit. As soon as your bit heats up it's nearly useless.

[Phil Salvati]

I use diamond bits made by Hitachi..... available at Lowes.

I get 3 or 4 holes done with no problem if you keep the bit wet in Marble. I have only used them on Granite once.... It seemed to have worked just as well. I use the 12" tiles for building markers... all four corners have bolt holes.... If this is the area you plan to drill.... DON'T use a hammer drill.... you are guaranteed to break it.

Build a damn of clay around the hole and keep water in it as you drill.

I use a Drill press, on very slow speed with a plywood backing.

GO slow and very light pressure.... just as you start to get bored... you will think...aaaahhh maybe just a little more pressure......you will break a few!

P

[Tom Bull]

Plumbers putty makes a really good coolant dam if you granite is not porous. Also turpentine is a good coolant for diamond core drills. There is a core drill system available that has a water feed by way of a small pump up sprayer, don't remember who makes it. Marble is much, much softer than granite. I have installed countless shower systems in all kinds of tile. The hardest thing to drill is some kinds of ceramic tiles.
A great trick for starting your hole, regardless of the kind of stone, is to use a ball shaped DIAMOND bit on a dremel tool to make a divot so the drill bit doesn't slide around.

[Alexander Stein]

Carbide tips are cheap, and wear fast too. Diamond Core Drills/Hole saws are the way to go for granite drilling. If you plan on cutting more holes in the future get a decent diamond bit. The bit may be pricey however you will end up saving money per hole in comparison to going through multiple carbide bits, or even multiple cheap low-quality bits.

Keeping the bit wet while drilling will prolong your diamond bit very much. Easiest way to do that is to take a water jug/bottle, put a hole(s) in the bottom side, then direct the water which pours from the bottle to the hole being drilled. (always use GFCI!)

I have a granite tool contact, PM for details.

[Dan Hintz]

Keeping the bit wet while drilling will prolong your diamond bit very much. Easiest way to do that is to take a water jug/bottle, put a hole(s) in the bottom side, then direct the water which pours from the bottle to the hole being drilled. (always use GFCI!)
Or use air tools, like I do... water and electricity together scares the bejebus out of me, GFCI line or not.

[Bill Cunningham]

Or use air tools, like I do... water and electricity together scares the bejebus out of me, GFCI line or not.

I spent 'years' teaching underwater electric arc welding.. My hair has straightened quite a bit since then though :D

[Belinda Barfield]

I would caution against putting a hammer drill anywhere near granite. Go to www.braxtonbragg.com (http://www.braxtonbragg.com) or www.granquartz.com (http://www.granquartz.com). Purchase a Metabo grinder and a core bit. Are you drilling holes for mounting screws, or larger holes? What thickness granite? If you are drilling larger holes pack the core bit with ice. The melting ice provides enough water to keep the bit cool. The secret to making your bits last is not overheating them.

[Dave Johnson29]

Belinda,

I have to agree with your advice, no hammer drill unless the driveway gravel needs supplementing. Does that sound like the voice of experience? :eek:

[Brian Knuckles]

Thank you everyone for their input!


Still broke a few tile & the ones i didn't I scratched...:mad: