An internal bend cable tray is a specialized fitting used to direct cables around interior corners or angles within a cable tray system. Hubbell's NEXTFRAME® Ladder Tray is the effective and widely used cable runway that supports and delivers bundles of cable between cabinets, racks, and closets, along walls, and suspended from ceilings. The Ladder Tray features light, rugged, tubular steel construction. It is designed for. Students trading aid on how best to put an internal 90 degrees bend in steel cable tray. more. Choose a cable tray fitting with a radius equal to or greater than your calculated minimum. Common standards are 300, 450, 600, and 900 mm. both of these items come in 3 metre lengths and can be cut with a hacksaw.