The roller chain sprockets can be divided into 3 styles with different outer diameters and technique data.
The type A roller chain sprocket has the simplest structure, which is plain and without any extensions on both side. It offers a stable and secure attachment to the shaft. The type B and type C roller chain sprockets have 1 hub extensions on 1 or both side to provide stability, and allow for the use of full-depth keyways and standard setscrews to attach the sprocket. They can also accommodate a wide range of shafts.