Direction of cable tray mounting nuts

Cable tray nuts, typically hex nuts, should be installed with the flat side against the tray or fitting, ensuring the threaded side faces the bolt for secure fastening.

Proper Orientation

When assembling cable trays, hex nuts (such as M8 DIN 934/ISO 4032) are used to secure bolts that connect tray sections, bends, or supports . The flat side of the nut should sit flush against the surface of the tray or bracket, while the threaded side engages the bolt. This ensures maximum contact area, prevents loosening, and distributes the load evenly.

Installation Tips

• Thread engagement: Ensure the bolt is fully threaded into the nut without cross-threading. Typically, at least 1.5 times the bolt diameter should be engaged for secure fastening.
• Torque specification: Follow manufacturer recommendations for torque to avoid over-tightening, which can deform the tray or strip threads.
• Washer usage: Use washers between the nut and tray surface to protect the tray from damage and improve load distribution .
• Alignment: Nuts should be oriented so that they are easily accessible for tightening and future maintenance. In vertical or overhead installations, consider using lock washers or nylon-insert lock nuts to prevent loosening due to vibration.

Special Considerations

Some cable tray systems, like clickable or interlocking trays, may not require traditional nuts and bolts . In these cases, the trays automatically align and lock, eliminating the need for manual nut orientation. For standard metallic trays, however, proper nut direction is critical for mechanical stability, safety, and compliance with IEC 61537 and NEN 1010 standards . By following these guidelines, cable tray assemblies remain secure, aligned, and capable of supporting the intended cable load safely.