Types And Uses of Base Jacks Base jacks are a versatile piece of equipment with significant advantages in terms of stability, safety, and adaptability in scaffolding systems, making them an essential component of scaffolding. Scaffolding base jacks, also known as leveling jacks or screw jacks, typically consist of a threaded rod, base plate, and jack nut, and can be used to level the scaffolding platform by rotating the nut to ensure stability.