What size should the cable tray hanger rod be

The typical standard hanger rod size for supporting cable trays is M8 (8 mm) or larger, depending on tray width, load, and span.Standard Rod Sizes and GuidelinesFor most cable tray installations, threaded rods of 8 mm (M8) diameter are commonly used for practical and structural reasons, especially for trays up to 600 mm wide carrying moderate cable loads . Larger trays or heavier loads may require M10 or M12 rods to ensure adequate support and safety. The rod material is usually galvanized steel to prevent corrosion and meet building codes .Support SpacingTypical spacing for ladder or wire mesh trays is 2 meters (6.5 feet) for standard loads, though this can vary based on tray width, cable weight, and manufacturer specifications .For heavier loads or wider trays, spacing may be reduced to 1.5 meters or less to prevent excessive deflection .Rods are usually installed vertically from ceilings or structural members, with tray ends formed downward for easy drop-in installation .Load ConsiderationsWhen selecting rod size, consider the total weight of the tray, cables, and any supporting angles or fittings. For example, a 600 mm wide tray with cables and support angles totaling 51 kg may be safely supported by four M8 rods, each carrying approximately 12.8 kg . Always verify the rod's yield strength against the expected load, factoring in safety margins.Compliance and Best PracticesFollow manufacturer instructions and local codes for rod selection and installation .Ensure rods are fully threaded and properly anchored to structural elements.Use appropriate hardware such as nuts, washers, and brackets to secure the tray.Consider corrosion protection (hot-dip galvanizing or zinc plating) for long-term durability . In summary, M8 threaded rods are standard for most cable tray installations, with larger diameters used for wider trays or heavier loads. Proper spacing, load calculation, and adherence to manufacturer and code requirements are essential for safe and reliable support.