Turn Buckle: Hook Straining Screw Adjusters. Twist The Body To Increase Or Decrease Tension. Used in many applications - marine - outdoor - wire riggings - catenary wire - rope tensioners, and so on. These are also known as Tensioners, Turn Buckles, Straining Screws, Barrel Strainers, or Open Body Rigging Screws. Specification: Material: Zinc Plated Mild Steel 14mm 8,000.00 16mm 11,000.00 18mm 14,000.00 22mm 12,000.00 24mm 20,000.00