25 Chain A Plate Sprocket – Size Chart

Posted on July 17, 2026 in FAQ, Size Chart

25 Chain A Plate Sprockets are flat, hubless sprockets designed for use with #25 roller chain. A Type A plate sprocket does not have a hub, making it a compact option for light-duty drive systems, small machinery, automation equipment, and applications where space is limited.

#25 roller chain has a 0.250″ pitch, also commonly written as 1/4″ pitch. When selecting a 25A plate sprocket, the key details to check are chain size, tooth count, outside diameter, bore size, and how the sprocket will be mounted or modified for the application.

25 Chain A Plate Sprocket Size Chart

What Is an A Plate Sprocket?

A Type A plate sprocket is a flat sprocket without a hub. Because there is no hub, A plate sprockets are useful where space is limited, where the sprocket needs to be mounted to another component, or where the bore needs to be machined for a custom setup.

For #25 chain, the sprocket pitch matches the chain pitch of 0.250″, or 1/4″. The tooth count changes the sprocket diameter, speed ratio, and chain wrap, which is why choosing the correct size matters.

Click Here – to learn how to measure the pitch of a roller chain with calipers.

Common Applications for 25 A Plate Sprockets

25 Chain A Plate Sprockets are commonly used in light-duty machinery, compact conveyors, small automation systems, packaging equipment, agricultural equipment, OEM builds, robotics, and custom fabricated drive systems. They are a strong choice when a small, flat, plate-style sprocket is needed and the mounting method is handled separately from the sprocket itself.

These sprockets are also helpful for machine shops and maintenance teams that need a blank or plain bore sprocket to modify for a specific shaft, weldment, fixture, or custom drive layout.