The dimensions of the steel cube are 18"x18"x18". The legs are made out of common 1-1/2"x 1-1/2" galvanized slotted angle. I used 3-72" slotted angles to make the cube with no waste as 18" goes into 72" 4 times. I used 16 1/4" x 3/4" carriage bolts with 16 lock washers and 16 1/4"x20 nuts to hold the cube together. As long as you cut the slotted angle through the slots, the holes will line up allowing for the bolts at all of the corners. I filed the sharp edges off of all the exposed corners for safety.
The top is made out of 3/4' pallet wood ripped down to 1-1/2" wide and put together butcher block style(with glue and screws then clamped until dry). The dimensions of the pallet wood top are 18-1/2"x 18-1/2" x 1-1/2" so it sits flush with the cube structure. The top is held on by 1" pan head screws from the bottom. I left the bottom of the top untouched and irregular on purpose while the top and sides were sanded flush. This table is extremely strong and and will hold up for a long time! The final finish is linseed oil and bee's wax so no V.O.C.'s to worry about!