# of Flanges: Describes the number of flanges on a pulley. Most will have two flanges, to keep the belt from slipping, but some operations work best without any flanges.
Back Side Offset: The width from the center of the pulley to the backside edge of the hub or bore adapter.
Bearing ID: The inside diameter of the bearing used in the pulley. This is useful for determining which bore adapters will work.
Finish: The finishing material used to prevent rusting in steel or cast iron. Zinc Plating and powder coat provide the longest rust prevention.
Flange Angle: The angle of the flanges on flat idlers. Presented in degrees from perpendicular.
Flat Diameter: The diameter from side to side of the flat of the pulley. This is the diameter where your belt will ride.
Flat Width: The distance from side to side of the flat of the pulley. This is the width where your belt will ride.
Frontside Offset: The width from the center of the pulley to the front edge of the hub or bore adapter.
Inside Diameter: The distance across the center hole, or bore, of the product.
Material: Describes what the product is made from. Plastic, aluminum, and diecast are softer than steel and cast iron.
Material Thickness: Refers to the thickness of steel products only. This helps determine the overall sturdiness of the part. For Idler Pulleys, material thickness greater than 0.07” is considered Heavy Duty. For Drive Pulleys, thickness of 0.14” or greater is Heavy Duty.
Outside Diameter: The distance across the face of the pulley, from outside edge to outside edge
Stickout: The distance from the edge of the pulley’s flange to the edge of the bore adapter or hub.
Throughbore: Length of the bore of the pulley, from one edge to the other. The Frontside Offset and Backside offset together equal the length of the throughbore.
Width: The distance from side to side of the pulley, across area where the belt rides