Best Price Hollow Galvanized Steel Adjustable Base Scaffolding Details of vertical screw jack 1. Vertical screw jack are made up of Q235 hollow steel which consists of cast iron nut ,metal sheet base plate and steel screw bar. 2. Vertical screw jack are easy to assemble and dismantle which can help you to save construction time and cost. 3. The CO2 electrical arc welding guarantee the welding part of Vertical screw jack is very sturdy and strong. 4. Vertical screw jack is ofthen used to support the scaffolding system. 5. There are many kinds of Vertical screw jack you can choose in our factory. Name Length/mm Diameter/mm Plate/mm Solid Jack Base 550/600/700 30/32/34 120*120*5 Hollow Jack Base 550/600/700 38/48 150*150*6 Solid U-head Jack 550/600/700 30/32/34 120 x 100 x 45 x 4 Hollow U-head Jack 550/600/700 38/48 150x 150x 50x 6