Tray-type cable tray hole dimensions

Standard cable tray connection holes typically range from 9 mm to 13 mm (3/8" to 1/2") in diameter, depending on tray type and bolt size.

Typical Connection Hole Sizes

Cable trays are designed with pre-punched holes along the side rails or flanges to allow bolted connections between sections, fittings, and supports. Common hole diameters include: 9 mm (3/8 inch) – often used for light-duty trays or smaller ladder and perforated trays. 11 mm (7/16 inch) – frequently used for medium-duty trays and standard bolted connections.

13 mm (1/2 inch) – used for heavy-duty trays, wide ladder trays, or installations requiring larger bolts for structural support. The spacing between holes is typically standardized to allow flexibility in alignment and secure fastening. For ladder trays, holes are often spaced every 50–100 mm (2–4 inches) along the side rails, while perforated or wire mesh trays may have slightly different spacing to accommodate their structural design.

Bolt and Fastener Considerations

Bolt size usually corresponds to the hole diameter: M8 or 5/16" bolts for 9–11 mm holes, and M10 or 3/8" bolts for 13 mm holes. Material thickness of the tray side rail affects the choice of bolt length and type. Thicker rails require longer bolts to ensure secure fastening.

Compatibility: Always verify that the connection holes align with the tray type and manufacturer specifications to maintain structural integrity and code compliance.

Practical Tips

When planning installations, consider future expansion and ensure that the hole pattern allows for additional tray sections or accessories. For heavy cable loads, use the largest compatible hole and bolt size to reduce stress on the tray and prevent deformation. Always follow manufacturer guidelines and local electrical codes (NEC, NEMA, IEC) for bolted connections to ensure safety and durability.

By adhering to these standard hole dimensions and spacing practices, cable tray systems can be securely connected, maintain structural integrity, and accommodate future modifications.