I built this table back in 1994 when I first opened my welding shop. It is built of 4" channel and 3"X 5" angle iron. There are also adjusters on the legs to level it and I installed 2' square tubbing receivers all around it so I can plug in and out special pieces of equipment, like my 6" vise. it can be plugged in any time, and removed just like you would add or remove a Ball mount from your trucks hitch.