Cable tray screw dimensions and specifications

Cable tray screws typically range from M6 to M8 in diameter, with lengths depending on tray thickness and mounting requirements, while fast-fit systems like Swiftclip may eliminate traditional screws.

Standard Screw Specifications

• Diameter: Most cable tray systems use screws with diameters of M6 (6 mm) or M8 (8 mm), depending on the tray type and load requirements .
• Length: Screw length varies with the material thickness of the tray and fittings, generally ranging from 16 mm to 50 mm for standard ladder or perforated trays. Longer screws may be required for mounting to walls, brackets, or supports.
• Thread Type: Coarse threads are common for metal trays, while self-tapping screws are often used for direct attachment to steel or aluminum tray components.
• Head Type: Hex head or pan head screws are standard, allowing secure tightening with wrenches or screwdrivers. Some systems may use captive or fast-fit clips to reduce installation time .

Fast-Fit Alternatives

Modern cable tray systems, such as Legrand Swifts, use Swiftclip or Swiftgrip fasteners, which replace conventional nuts and bolts. These clips:

• Require only two clips per joint for secure assembly.
• Eliminate the need for separate screws in many cases.
• Are designed for quick installation, reducing labor and component count .

Considerations for Selection

• Tray Type: Ladder trays may require larger screws for rungs and side rails, while perforated or channel trays may use smaller screws.
• Material: Aluminum trays may use stainless steel screws to prevent galvanic corrosion.
• Load and Environment: Heavier cable loads or outdoor installations may require longer or higher-grade screws. In practice, always verify the manufacturer's technical guide for the specific cable tray system, as screw dimensions and fastener types can vary between brands and tray models .