01-11-2016, 04:34 AM
I had been using a Hitachi DH 40FA rotary hammer until I overheated it and it stopped working. It was working well though. The drill bit I have would allow me to go up to 18" deep but I go down not quite a foot or so. The T-bar has a flat plate on it about 10" up that prevents driving it in any further. If you're driving it into solid rock 6" would be enough.