Conveyor carrying idlers

Belt width determines idler roll length. Standard widths include 18, 24, 30, 36, 42, 48, 60, 72, 84, and 96 inches.

Carrying idlers support the loaded belt on the top run. Determine if you need equal troughing idlers (standard material support), impact idlers for loading zones, flat idlers for sorting or picking applications, or self-aligning idlers for tracking correction.

If replacing a troughing idler, measure the angle between the center roll and wing rolls. Common troughing angles are 20°, 35°, and 45°.

Calculate the required CEMA rating (B, C, D, E, or F) based on belt width, material density, belt speed, and conveyor length.

Standard roll diameters range from 4 to 8 inches, depending on CEMA class. Higher belt speeds and heavier loads require larger diameter rolls.

Note whether your existing carrying idlers use standard top mount (conventional bracket mounting) or channel inset mounting (low-profile installation for clearance-restricted applications).

Match bearing type and seal configuration to your operating environment.

Standard steel rolls suit most applications. Specify rubber disc, rubber-cushioned, or polyurethane-coated rolls for sticky materials, impact absorption, or abrasion resistance. Choose galvanized or stainless steel frames for corrosive environments.

Verify your current carrying idler spacing (typically 3–5 feet on standard runs, 1–2 feet in loading zones) to control belt sag.