When I built my bench I had some 2x12 bullnosed stair treads that were never going to to be used so that is what I used. You could park a battleship on it and there is no problem with putting something in the vise and grabbing a 24 inch Crescent wrench or pipe wrench and applying all the torque you want. It aint going anywhere! I hate a wimpy bench that you are afraid of hurting.