I have my presses mounted on thick plywood... 5/8 - 3/4 inch... carriage bolts recessed from underneath. I use a couple of big **** C clamps to hold it to the bench. I left the C lamp spot as a gap but finished the edge with an aluminum strip to keep cases and primers from going to the floor. Over many years, I've been glad I didn't bolt it to my bench top directly... like I did on my first couple of benches.