Heavy Duty Portable Tables have a 2" x 3/16" angle iron frame for added strength. Shelves are reinforced and have lips down. (2) swivel and (2) rigid bolt-on casters. Sturdy tubular push handle for easy maneuverability. 4,000 lbs. capacity unit has welded 14 gauge steel shelves with channel formed sides. 5,000 lbs. capacity unit has welded 12 gauge steel shelves. FOB Shipping Point.