Hi, Michael. Those things are called Lolly Posts or Lolly Columns and I'm sure that there is some local usage in the names. In any case, I have bought them both at Home Depot and Home Quarter. You might have to ask where they are. I also know that structural steel suppliers carry them in heavier versions than the home centers. The places local to you that sell steel beams should be able to help you if the home centers can't. By the way, I have bought them to go into assembled lengths of 2 foot up to 8 foot from the home centers so you will want to know the rough length you want to purchase as they are wildly adjustible. It is also a good idea to get some pressure treated 2x lumber to spread the weight over the floor and possibly some 4x4's if you have a whole section of joists that you have to raise.