Double pitch sprockets

As shown in the figure, when each roller skips a tooth, and the number of teeth of the sprocket is odd, the chain roller uses different teeth each time it rotates. The mechanism can prolong the service life of the chain wheel and reduce wear.
The S-type roller chain can be used with more than 30 standard roller chain sprockets with upper teeth.

For these sizes, the Roller Diameter and Inner Width are the same as the single-pitch version. But the pitch is twice the size (hence the term “double-pitch”). Because of the pitch difference, the pressure angle on the sprocket is different from the single-pitch version. Therefore, for tooth counts of 30 or less, a “double-pitch sprocket” must be used for a “double-pitch chain.” For 31 teeth and above, a double-pitch chain can use any standard single-pitch sprocket without any operational deficiency.

For example, a C2060H chain will engage appropriately with a 60B33 sprocket. However, the same chain cannot engage with a 60B17 sprocket; in this case, a 2060B17 sprocket must be used.

It is important to note that standard roller double-pitch sprockets are double-duty, meaning there are two teeth per pitch. That means that the adequate number of teeth is half the actual tooth count.

A large roller chain cannot run on the single-pitch equivalent; for example, a C2042 chain cannot engage with a 40B15 sprocket. Because the roller is more significant, it will not “seat” correctly in the sprocket tooth. Because of this, specific sprockets must be ordered for sizes C2042-C2162H.