Drilling into concrete

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3,179
Location
West Michigan
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Need to make some 5/8" holes in a concrete slab. I have a 5/8" masonry bit which will fit my 1/2" chuck on my hammer drill. What I am unsure of is whether concrete would benefit from a pilot hole or if that would negatively impact the finished hole or drilling process?
 
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434
Location
Cheshire, England
As masonry drills can wander, I always use a pilot hole for accuracy and it drills easier particularly if your hammer drill is not overly powerful.
 
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4,786
Location
NJ
Not all hammer drills are the same. I had a Craftsmen and I struggled to drill into my foundation to hang a TV. It died and I picked up a cheap HF hammer drill. That cheap HF hammer drill is way more powerful than the Craftsmen. Although, and me an concrete drilling don't get along that well. Can't tell you how many times I've drilled the hole and need another 1/4 inch and it just won't go any deeper.
 
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1,627
Location
Cincinnati, USA
If you need very accurate spacing you might start a very shallow hole with a smaller bit, then switch over to the desired size, but other than that no you don't need a pilot hole.
 
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1,532
Location
MD
Originally Posted by 65f100
You need a rotary hammer instead of a hammer drill.
What? My experience is the opposite.
 
Messages
3,179
Location
West Michigan
Thread starter
Well just finished. My 1/2in hammer drill worked great with a masonry bit. No pilot hole, just started slow and it didn't want to wander at all. Nice tight, clean bore that my anchors grabbed nicely.
 
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