Wow, I built almost the identical thing a few years ago. Wanted a bench to put a small lathe onto while still having a copious amount of non-machine workspace.

Wow, I built almost the identical thing a few years ago. Wanted a bench to put a small lathe onto while still having a copious amount of non-machine workspace. On the top I used 2x12's though. And (as a complete novice at the time just putting "lego blocks" together sourced from Home Depot), I just used regular screws to hold it together. That thing has moved with us for the past few moves. Super heavy. Also (not literally) bulletproof. Thanks for the description on your build.