I am having trouble drilling 5/16 holes in my garage floor. I have ruined 5 drill bits. It starts out good and then the bit becomes dull. I am going slowly and using water to cool the bit. The man at the hardware store told me that as soon as the bit contacts a stone it will become dull. Help please !
Drilling concrete
- Thread starter elba
- Start date
LegacyIndustrial
ALLIANCE MEMBER
You need a hammer drill with a masonry bit. You can rent it if need be.
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jimgood
Well-known member
Are you using masonry bits?
dutchgray
Well-known member
What bits are you using?
You should be using a rotary SDS hammer drill with masonry bits, concrete should be pretty easy to drill, its only when you hit rebar you have a problem.
You should be using a rotary SDS hammer drill with masonry bits, concrete should be pretty easy to drill, its only when you hit rebar you have a problem.
mitusa
Well-known member
This^^^^^ Or buy one; they come in handy!
LegacyIndustrial
ALLIANCE MEMBER
If you will have low use, try harbor freight for a good deal.
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I get great use from Bosch bits in my hammer drill. I don't even know how many holes I've drilled in concrete with them. In fact, I had to drill into some stones in a wall last year, to attach something, and they did great there, too. Before I bought a hammer drill, I severely hated drilling into concrete, and now it's just a quick job and it's done.
va.grouseman
Well-known member
Yes, hammer-action.---Strait spinning of even the best masonry bit will only get you through that, (what was that sweet pure grout on top of the concrete at the time of the pour), and then you hit rocks.---And where I live that is hard blue granite from the nearby quarry and that's where the drilling stops unless I have that good hammer action.---My 36 volt Dewalt hammer-drill does a good job, but the bits will still eventually dull, or the carbon starts popping off, pounding on that granite.---You can't hardly drill through a soft cinderblock with just strait drilling.
hh76
Well-known member
Rebar? That'll do it to masonry bits.
theoldwizard1
Well-known member
Your hole size may not be accurate, but you would have been done a long time ago. (That is a "star drill" and a drill hammer.)
And when you get done you will have something in common with John Henry.
And when you get done you will have something in common with John Henry.
That was going to be my guess as well, rebar can be a *****! they make rebar eaters, just stick a magnet in the hole, if you feel it stick, youll have to go that route, masonry bits will never get it