Drilling into concrete spur post

I've drilled a hole in my concrete 4" square post. I clamped a piece of wood against it to avoid an exit wound. and switched off the hammer action on the drill. The problem is, that theyr'e re-inforced with wire, and you may hit one & i trusted to luck!! not sure how to detect a wire in concrete.

Yes. Go gently, from each side, with a pilot drill, then enlarge, also from each side. You need to be able to drill straight, obviously! To assist this, a piece of batten pressed up against the post is useful to line up the bit.

You should not get an exit crated when drilling through walls - the outside should be propped to prevent this, and pilot holes should be drilled carefully. OK, I know... try telling *that* to the television aerial man.

Actually, I might not use an SDS drill in this case, just an "ordinary" hammer drill, using sharp bits.

It's put in at the corners, or the slot edges for slotted posts, and held in place in the mould with plastic Xs. (the wire goes through the middle of the X).

Thanks for your replies. Al