# drilling into stone



## kevbo (Jun 26, 2007)

What would be the fastest method to drill a 2" deep by 1/2" hole into river rock? Tried Carbide 1/2", roto and high speed...to slow, went and got a wet diamond bit.. even slower!!


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## firemike (Dec 11, 2005)

Are you using a good hammer drill?


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## Kent Whitten (Mar 24, 2006)

They make diamond core bits for this. Don't use rotohammer types. It's just like a plumbers hole saw except with diamond tips on them. Goes in pretty easy


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## jvcstone (Apr 4, 2005)

If you do go with the diamond core bit's, you need to know what kind of rock is in your river. A different technology for attaching the diamonds to the matrix is used for hard (granite types) vs. soft types (Marble). If you couldn't drill it with a rotary drill, it most likely is of the granite type, but some marbles would need a rotary hammer drill with the carbide drill bit.

JVC


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## Tscarborough (Feb 25, 2006)

A star drill, a 3# hammer, and a big fattie.


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## firemike (Dec 11, 2005)

The rocks we have here in Michigan don't appear to be too hard, I can drill through a 6 to 8 inch rock with a 1/2" bit in my Bosch in a minute or two. My wife does crafts and makes fountains out of rocks, hence the hole(s) for the water tube.

If it were granite or some other harder rock, you might need a different approach as jcvstone said.


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## kapena (Aug 20, 2004)

Have you tried a 1/4" pilot hole with a hammer drill first? The fatter 1/2" bit should go pretty easy later, even in hard stuff like basaltic rock. Granite would be a different story though.


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