Hook Clamp - Doughty Engineering This Dought Clamp is a double ended 180-degree twist hook clamp. It comes in five sizes to fit various requirements. Manufactured from high-quality steel, it is simple to use and extremely strong. Ideal for general use in theatres and stage productions. This range of Doughty hook clamps is available in Zinc-plated finish or Black paint on request. It is possible to manufacture special sizes to your specification. For any inquiries, please contact us via chat. Specifications: Sizes: 150mm Centres, 225mm Centres, 300mm Centres, 450mm Centres, 600mm Centres SWL: 40kg Width: 25mm Tube Diameter: Ø48 - 51mm Other Dimensions: Refer to the image Material: Steel Finish: Available in a bright zinc plated finish or black powered paint on request All Doughty Hook Clamps are Stamped with SWL.