Plastic or Metal Roller End Caps

Question One: How Heavy Is the Load per Roller?

Divide the package weight by the rollers in contact, then apply the impact coefficient for how the product is loaded. Carton and tote work usually lands well inside what a moulded housing carries. Pallets, steel stock and weldments do not, and those runs want a metal housing such as the MTR range.

Question Two: How Hot Does It Get?

Moulded housings lose strength as temperature rises, which is why they are the wrong choice at oven exits, near hot parts or in direct sun on an outdoor deck. Steel housings tolerate far more. Where you are unsure, measure the part temperature rather than the room.

Question Three: How Loud Can the Line Be?

On a long dispatch run, steel end caps make a noticeably louder line than moulded ones. In a packing hall with people working next to the conveyor all day, that difference is a real complaint, and it is the most common reason lines are converted to plastic housings.

Question Four: Is It Wet?

Moulded housings cannot corrode, which makes them the safer choice in humid warehouses and unheated dispatch bays. The bearing inside still needs protecting from direct water jets, so a plastic housing is not by itself a wash-down specification — for that, look at stainless components.

Getting the Fit Right

Whichever you choose, three dimensions must match: the roller tube inside diameter for the press fit, the bearing bore for the shaft, and the shaft form for the frame slot. Two out of three is a roller that fits and fails early. Press fits also lose grip once a cap has been pulled, so a rebuild uses new caps rather than the old ones refitted.