Need a super sturdy, adjustable clamp or fixture for a CNC machine, woodworking jig, or heavy-duty workbench? This T20 lead screw set is built like a tank. The lead screw, nut, and base are all made from 45# carbon steel with a black surface finish, so it can take a beating. The screw is 20mm thick with a 4mm pitch, meaning one full turn of the handwheel moves it 4mm for precise adjustments. It comes with a nice, foldable 100mm diameter aluminum alloy handwheel that's easy to grip and tucks away. You can choose from a bunch of total lengths: 220mm, 250mm, 280mm, 300mm, 350mm, 400mm, 500mm, 550mm, or 600mm (the effective stroke is shorter, as listed in the description). It's simple, strong, and has a huge load capacity. Perfect for DIYers, machinists, or anyone building industrial tools. Just pick the length you need and bolt it into your project. Comes as one complete set.