Idler sprockets are used to guide the chain, maintain tension, and keep a drive system running smooth. They don’t transmit power — they simply stabilize the chain path and reduce wear on the main drive components. Below are the common styles you’ll see in chain-driven equipment.
A-Type (Plate) Idler Sprockets
A-type idler sprockets, often called plate sprockets, are flat and hubless. They’re simple, compact, and easy to mount wherever space is tight. Because there’s no hub, they offer more flexibility for custom setups and low-profile designs.
Allowed comparison:
Compared to regular sprockets, A-type idlers have no hub, giving them a thinner, cleaner profile that fits well in tight chain layouts.
B-Type Idler Sprockets
B-type idlers include a single hub on one side. The hub provides a stable mounting point and adds strength and rigidity. This style is commonly used where alignment matters and the sprocket needs to stay solid under load or higher speeds.
Stamped Idler Sprockets
Stamped idler sprockets are formed from sheet steel, making them lightweight and cost-effective. Even with the lighter design, they still provide reliable chain engagement and are widely used in OEM equipment, conveyors, and general-purpose machinery. Many stamped idlers include built-in bearings for quick installation.
Picking the Right Style
Choose based on chain size, load, and space. A-type works well when you need a thin profile. B-type is the better fit when the system needs a strong, hubbed mounting surface. Stamped idlers are a good option for lighter applications or when you want a simple, economical solution.