Sprockets could be classified into typical sprockets, HK sprockets as well as other sprockets.
1. Conventional sprocket
Normal sprockets are ANSI sprockets which might be engaged with common series roller chains. See P125 for dimensions.
You can find two forms of tooth profiles: U-tooth and S-tooth.
2. HK sprocket
HK sprockets may be engaged with HK series roller chains, and these for single strand chains are identical to standard sprockets. Nevertheless, sprockets for numerous strand chains are diverse from common sprockets in sprocket tooth profile.
three. Other sprockets
Other sprockets are made according towards the 
following calculation formulas to suit respective specialty chains.
The sprockets used for that following chains would be the identical since the normal sprockets in tooth gap type, but distinctive in tooth thickness (sprocket tooth profile).
4. Calculation of sprocket dimensions
The dimensions of normal sprockets together with other common sprockets are calculated as follows. At first, the diameters of sprockets are calculated from your following calculation formulas.
Next, sprocket tooth profile (the shape on the tooth based on its thickness) is calculated from your following calculation formulas. (The values shown inside the following pages have been calculated by these formulas and regarded as the typical values.)
Calculation formulas for diameters and tooth gap kinds Calculation formulas for diameters
Calculation of pitch diameter, tip diameter and caliper diameter
The essential dimensions of the sprocket suitable for any chain pitch of 1 mm are respectively called pitch diameter component, tip diameter factor and caliper diameter element. The respective components for respective numbers of teeth are listed below. If these things are multiplied by chain pitch, the basic dimensions on the corresponding sprocket could be obtained.
Example:
In the situation of 80 (25.40 mm pitch) with 35 teeth Pitch diameter (Dp) ＝ P×Pitch diameter aspect
Calculation formulas for tooth gap types
As the most rational tooth gap varieties through which the strain angle improvements in response to the elongation of a smoothly rotated roller chain with all the lapse of support time, ANSI specify two kinds of tooth profiles: U-type and S-type. Normally, S-type tooth profiles are adopted in accordance with ANSI, and our common sprockets also have S-tooth profiles.