Methods for constructing right-angle and 90-degree cable trays

Right-angle and 90-degree cable tray bends can be constructed using mitered cuts, flat bends, or live on-site modifications, with careful cutting, bending, and bolting to ensure structural integrity and safety.

1. Mitered or Fabricated 90-Degree Elbows

A common method for creating a 90-degree elbow involves cutting two 45-degree angles on a straight tray section and joining them to form a right-angle bend. This technique, often called a fabricated or mitered bend, allows for smooth directional changes in cable routing while maintaining tray strength. After cutting, the pieces are fastened together using bolts or rivets to secure the elbow .

2. Flat 90-Degree Bends

Flat bends are constructed directly from a straight tray by following these steps:

• Mark the tray along the intended bend line.
• Remove part of the tray lip (approximately 2¾ of the tray width, split evenly on both sides) using a hand grinder or file.
• Cut down the center line carefully to avoid tray deformation.
• Flatten the tray lip at the bend point using a blunt object.
• Bend the tray to 90° and bolt the two parts together.
• Add a gusset by cutting a piece of tray to fit the internal edges and bolting it to reinforce the bend .

3. Live On-Site Bends for Wire Mesh Trays

For wire mesh or basket-type cable trays, bends, tees, crosses, and reducers can be made directly on-site using a bolt cutter. The cutter trims the wires while forming a protective zinc layer on the cut ends. Rubber caps can be added to protect exposed edges, ensuring safety and maintaining electrical protection .

4. Cutting and Safety Considerations

• Use band saws or angle grinders for cutting metal trays, taking care to avoid overheating and sparks. Band saws are preferred for low-height, thin metal trays, while angle grinders offer flexibility but require careful handling .
• Always wear Kevlar gloves, eye protection, and other PPE to prevent injuries from sharp edges or flying debris.
• Avoid mixing cutting blades between different metals (e.g., stainless steel and galvanized steel) to prevent galvanic corrosion .

5. Assembly and Reinforcement

• After bending, bolt the tray sections together securely.
• Use gussets or reinforcement plates at the bend to maintain structural integrity.
• Ensure that all cut edges are smoothed or capped to prevent damage to cables and maintain safety standards. By following these methods, installers can create durable, safe, and precise 90-degree bends in cable trays, whether using pre-fabricated elbows, flat bends, or live on-site modifications.