How is it done? I have a hammer drill and what I believe are proper (masonry) bits, but the spade on the bit is worn to nothing on the first hole. Everything on the Googles shows drillling cinder blocks n stuff. I am drilling old but solid concrete with lots of stone aggregate. Holes are less than 1/4 inch wide and 2 to 3 inches deep.
It's drilling concrete with aggregate. Hammer Drill and a masonry bit is the best you'll do. If you are talking cordless hammer drill well you might as well just beat on the end of the drill bit with your flaccid wiener. There isn't enough impact in the hammer of those things to do much good. It's also possible that someone put the rebar up to high and you have managed to be drilling into the top of one.
Corded rotary hammer (hammer drill) and the proper bit. Tool rental places will rent you a BFD if you need one. (Big F-in Drill)
Cordless is fine as long as it's an actual rotary hammer and not a 1/2" drill with a hammer function. Drilled all the 7/8" holes in my slab to put my lift in with a Milwaukee SDS 18v rotary hammer. One 5ah battery got the 14 holes drilled no problem.
3000 PSI is the 28 day design strength. Concrete continues to harden for YEARS. 5o year old concrete that isn't exposed to weathering can be some hard a$$ stuff.
We always borrowed a big bitch Milwaukee hammer drill from an electrical contractor when we needed to set new hoists.
Go to home depot, rent an SDS drill and be done with it. Harry homeowner hammer drills just aren't up to the task, and all you'll do is wreck your own shit. Been there done that (Makita 18v 1/2" hammer drill sent to destination fucked). You might get away with a couple 1/4" holes here and there, Or pre drilling for some tapcon's but if you've got a bunch to do in old hard concrete, just rent one. Or like I do buy one used with the plan to sell it when I'm done, but never do.
You can find a used Hilti TE 15 for around $250, they're $750 new. You'll never buy another one, they last a lifetime. The only drawback is you have to use Hilti drill bits. I've had good luck with the Dewalt cordless hammerdrill, as long as you have a good bit.
Ok, so the jist of what I am reading is that my experience is not abnormal, and my flaccid weiner is better than the corded Harbor Freight Hammer Drill I have been using. I'll rent a proper hammer drill for the rest the install. Thanks guys.
Make sure you have bits that aren't crap too. They're never sharp but it sucks to have a good drill shatter a bit on you.
That's how I finished my 3/4" holes after cooking my makita. Bought a bunch at a yard sale. Only had about 2" left to go for some floor anchors for my bender. It was surprisingly fast, but man invented hammer drills, and SDS drills for a reason.