Folks, I'm trying to drill 5/16" dia holes in stone to set post anchors but it isn't going well. My masonry bits are a (new) 1/8" Tapcon bit to drill a pilot hole and a 5/16" masonry bit to open it up, but an hour of drilling has only yielded a hole 1/2" deep and the Tapcon bit is shot. Would using a hammer drill make much difference? Are there better bit options? I've got 18 holes to drill and the path I'm on is not going to get me there.

I would start with a smaller bit and work up to the 5/16"

A hammer drill is the answer.

X 2 on the hammer drill.

Concrete bits wear out fast. Hammerdrill with a 5/16" bit should work fine. Unless you happened to center your hole on a hard rock/gravel or a piece of rebar.

Lubricate the hole.

Hammer drill

hammer drill with a good 5/16 bit should drill anything masonry or rock very quickly, thing about these bits is they do not like fast speeds and they take almost no pressure to work in a hammer drill.

yes hammer drills make a masonary bit work

yes bits have limited life , they rely on being hammered into the rock if you only spin them then you are grinding them off more.

a spray bottle with water can help keep dust down , cool and lubricate the bit.

Hammer drill will blast right through it. Like drilling a 2X4

What are you trying to do? Do you have to drill Into STONE?

take the dang drill out of reverse, and put it on forward...lol.... seriously

LOL

I know a guy who put the skill saw blade In backwards and couldn't understand why It wouldn't cut.

I shoved at a drill in reverse more than once..lol

Beav, I'm putting a railing around my front porch. The porch is an elevated concrete slab on concrete block with rock facing at the perimeter and on the vertical block faces. The posts holding up the porch roof land on the rock at the perimeter leaving me no other choice but to anchor into the rock. The original posts were just set/not anchored but there was no railing so it didn't really matter.

Hammer hammer hammer drill

Got ya.

I think tomorrow I will borrow my neighbor's hammer drill.

Thanks guys

You need a rotary hammer drill, carbide spade bit's for stone/masonry, and NO pilot holes. What kind of stone is it? Wouldn't hurt to have air and/or water to shoot down the hole.