2x � 15-21mm U Bolts - Zinc Plated Steel - Suitable for External installs Overview: Commonly used to secure pipework and poles to brackets, walls and chimneys, our high grade/heavy duty U-bolts are made from zinc plated passivated steel and come in various sizes and quantities. A full diagram of size specifications can be found on the picture above but if you are unsure of anything, please feel free to get in touch. Technical Specification: Minimum Diameter of pole that is compatible - 15mm Maximum Diameter of pole that is compatible - 21mm Length of thread - 30mm Diameter of thread - 6mm Made from - zinc plated passivated steel Nuts are supplied as pictured