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hidrate t1_j208jxg wrote

You need a hammer drill to penetrate into concrete and masonry.

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Sleepy_C OP t1_j2096yz wrote

Is a hammer drill the same thing as an impact drill? My nearby tool rental place has impact & rotary drills, but nothing called a hammer drill specifically.

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BigDan1190 t1_j20a9eu wrote

For concrete you want an SDS drill, try that term instead.

Edit: also watch some videos on YouTube on the difference between different types of drills and how to drill walls without hitting anything such as pipes and electric cables.

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Intelligent_Ebb4887 t1_j209r0i wrote

No, hammer drills are different. If you have a harbor freight, their cheapest one is about $35. You'll probably need additional masonry bits as well.

When using the masonry bit, dip the tip in water every 1-2 minutes, it will keep the bit from getting too hot and wearing out as fast.

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Sleepy_C OP t1_j20ac3k wrote

Okay awesome, I'll go in and ask in person then and see what they've got. Thanks the advice!

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puterfixer t1_j20nedp wrote

There are a few technologies for hammer drills. Generally you have a selector button on the side if you want just drilling or also with hammer function, or in some cases just hammer (bit doesn't rotate, useful for chisel-like bits).

One simpler technology does the hammering through a couple discs with a Z profile - the rotation of the motor plus your force of pushing the drill towards the wall gives the bit some light hits. These make a lot of noise and not too much progress in hard concrete, and your arms will go numb. I don't think I have ever seen one advertise the impact force or, if it did, it was rarely above 1J (Joule).

Then there's the other kind, which generates the impact force either mechanically or pneumatically. They are generally bulkier and seem to have a secondary motor perpendicular to the drilling axis. These go easily into 2,5-3J. They are not so loud, but VERY efficient. Just be careful at first, the drill will feel like it's pushing you back a few inches ehen it reaches the concrete layer, hold steady so that you don't break it. The SDS mandrel helps (instead of the classical drill bits).

Borrow or rent one for a few holes. If you need one more frequently or want to own one, look for Lidl's promotional periods when theybput on sale their Parktool model, it is excellent for its price without breaking after the 5th use.

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Sleepy_C OP t1_j21awp0 wrote

Awesome summary thanks. It's definitely for just these four holes so I'll opt to rent. But that's super helpful.

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cieg t1_j21hn8n wrote

You can use an impact with a masonry bit.

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Intelligent_Ebb4887 t1_j21qekf wrote

You could also use a regular drill. It's just not as effective.

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cieg t1_j23h0ml wrote

I’m in construction and especially for small projects like this an impact works great. If there’s a neighbor or friend with an impact they can borrow to drill four holes in brick or concrete it doesn’t take but a few minutes to do. If you need to drill hundreds of holes, definitely go buy a quality hammer drill or root hammer. Depending on the hardness of concrete, or if there’s rebar involved, yes, you should get the heavier duty drill.

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GrimResistance t1_j246woi wrote

For anything up to maybe a 3/16" bolt I wouldn't bother buying a hammer drill if you've already got a regular drill.

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Intelligent_Ebb4887 t1_j252zks wrote

The TV mount that I just installed on a brick wall required 3/8" holes for the anchors.

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TheYoung_Wolfman t1_j20klv0 wrote

Hammer Drills are also called Rotary Drills, Rotary Hammers, or SDS Drills. If you plan on staying at this house for awhile, I'd invest in a cheap hammer drill to keep on hand.

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tminus7700 t1_j23512v wrote

Yes. I have found that you can drill into a rock in the cement. The rock is often much, much harder than the cement. And that will greatly slow down a typical carbide drill without hammering.

Also be very sure the wall is not pre-stressed concrete. If it is you can severly compromise the structural strength. My daughter bought a fairly new house in Las Vegas. The garage floor is pre-stressed concrete and has a warning molded into the front main florr near the door that says to not cut or drill into it.

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