Cable tray bolts must be selected based on mechanical load, environmental conditions, and compliance with standards such as NEMA VE 2 and DIN EN 61537.

Bolt Selection and Material

Bolts used for cable trays should be mechanically strong and corrosion-resistant, typically made from stainless steel, galvanized steel, or aluminum depending on the installation environment . For outdoor or corrosive environments, stainless steel or hot-dip galvanized bolts are preferred to prevent rust and maintain structural integrity . Bolt material should match or be compatible with the tray material to avoid galvanic corrosion.

Bolt Size and Type

The bolt size depends on the tray type, load, and support structure. Commonly used bolts include hex head bolts, carriage bolts, and machine screws with corresponding nuts and washers . While specific diameters are determined by the tray manufacturer and load requirements, typical sizes range from M6 to M12 (metric) or 1/4" to 1/2" (imperial) for standard industrial cable trays . Always follow the manufacturer's recommendations for bolt diameter and length.

Installation Considerations

• Torque: Bolts should be tightened to the manufacturer-specified torque to ensure secure fastening without damaging the tray or support .
• Spacing: Bolts are used to secure trays to support brackets, wall mounts, or ceiling hangers. Proper spacing ensures load distribution and prevents sagging .
• Washers and Locking: Use washers to distribute load and prevent loosening. Lock washers or thread-locking compounds may be used in high-vibration environments .
• Compliance: Installation must comply with NEMA VE 2, UL 568, and DIN EN 61537 standards, which define mechanical strength, environmental resistance, and safety requirements for cable support systems .

Summary

When selecting bolts for cable trays:

1. Choose material suitable for the environment (stainless steel for corrosive areas).
2. Select size and type according to tray load and manufacturer specifications.
3. Ensure proper torque and spacing during installation.
4. Use washers or locking mechanisms to prevent loosening.
5. Follow relevant standards (NEMA, UL, DIN EN) for safety and compliance. Proper bolt selection and installation are critical to maintain the structural integrity and safety of cable tray systems in industrial and commercial electrical installations .