Anchoring strong-tie 4X4 post base into concrete tomorrow. Need to drill depth of 2 1/4″ @ 3//4″ diameter for lead shield. I have a Bosch SDS and a cordless hammer drill available. The pad of concrete was poured 24 years ago.
I saved ten bucks by opting for a concrete bit to use with the cordless instead of the expensive SDS bit. That set-up failed, Should I have gone with SDS? The 3/4′ concrete bit went nowhere with the 1/2″ cordless drill in dual mode after one minute of drilling. I’ve seen good performance with this set up but have never drilled more than a 7/16′ bit.
any thoughst would be welcome and appreciated
regards
CarpNotes
Replies
Carp
Rotary hammer drill and don't lean on it, let the drill do the work.
I use Hilti but Bosch certainly will have the balls for the job. Proper bits and tools aren't cheap, but neither is your time.
Get an SDS bit, that will work for sure. Or try drilling a smaller hole first with the hammer drill, before getting out the big bit.
A lot has to do with the makeup of the concrete. Some has small aggregate or aggregate that fractures easily, and that can be drilled with a standard drill, within reason. But if you have large aggregate that doesn't readily fracture you need a "real" hammer drill (or the good ol' star drill and hammer).