Assemble the bench legs and bolt them on to the top loosely. Because we’re bolting on shelving that the bench isn’t specially intended to have we’re adding a couple side braces that I cut from square steel tube, sanded, drilled, filed, primed, and painted months ago.
Measure and get all corners the same distance from the bench top edge, tighten a couple bolts on each top cross bar so nothing moves and use a punch to mark where to drill for threaded inserts.