The (12 gauge) leg-base is fastened to the tabletop with 4 heavy-duty screws which gets inserted into the frame using a strong welded hangar bolt. NPS Steel Heavy Duty Tables are built to last and made for the toughest environments. The legs adjust in 1” increments and are locked firmly in place with 2 K-9 external tooth lock washers and heavy duty tamper-free hex screws.