Tackit, When Cgottosaid said oversized hole in a earlier post I'm pretty sure what he meant was to make sure the hole in the steel plate was at least a 1/6" bigger than the hole that you drill into the concrete, Otherwise the anchor itself will get caught on the steel plate.
The anchors are a tad bigger than the hole you drill in the concrete.
Like S Berry said, Do not pilot drill and use a 1/2" bit for a 1/2" anchor.
Cgotto6, I have never heard of a ROTO Hammer, Here in the big city we call them a Hammer Drill.
Everything you just said us correct. Thanks for clarifying. Over size the flange hole so the drill bit and anchor both freely pass through. If you do you risk cracking the carbide tip. I have heard them called a hammer drill also, but around here roto hammer is the common name. I wonder if the first one made was branded or named roto hammer? Or us Washingtonians are just nuts haha.