Direction of cable tray connecting bolts

Cable tray bolts, such as truss-head bolts and combination nuts, should be installed so that the bolt head is accessible for tightening and the nut is secured on the opposite side, ensuring a firm and safe connection.

Proper Bolt Orientation

When connecting cable trays or attaching fittings:

• Truss-head bolts are typically inserted through the holes in the tray or joint plate with the bolt head on the accessible side. This allows for easy tightening with a spanner or torque wrench and ensures the bolt does not interfere with cable placement inside the tray .
• Combination nuts are threaded onto the bolt from the opposite side of the tray or fitting. The nut should be fully engaged and tightened to prevent loosening under load or vibration .
• For splice plates or joint plates, bolts should pass through the aligned holes of both tray sections, with the bolt head facing outward and the nut on the inner side or opposite face, depending on accessibility and clearance .
• In perforated trays, ensure that the bolt passes through the perforation and that the nut is tightened without deforming the tray edges. If unperforated trays are cut, the holes must be re-drilled before bolting .

Additional Considerations

• Accessibility: Always orient bolts so that future maintenance or adjustments can be performed without removing the tray or other components.
• Load and Safety: Proper bolt direction ensures the tray can support the weight of cables and withstand mechanical stress without sagging or loosening .
• Fittings and Covers: Some fittings, such as vertical bends or T-pieces, may have pre-mounted turn buckles or require specific bolt orientation to maintain cable protection and system integrity . By following these guidelines, cable tray systems remain secure, stable, and compliant with installation standards, while allowing for safe cable routing and maintenance.