Sprockets is usually classified into typical sprockets, HK sprockets and various sprockets.
1. Conventional sprocket
Typical sprockets are ANSI sprockets which could be engaged with standard series roller chains. See P125 for dimensions.
There are two styles of tooth profiles: U-tooth and S-tooth.
2. HK sprocket
HK sprockets is usually engaged with HK series roller chains, and individuals for single strand chains are identical to regular sprockets. Nevertheless, sprockets for various strand chains are distinct from regular sprockets in sprocket tooth profile.
3. Other sprockets
Other sprockets are developed according to 
the following calculation formulas to suit respective specialty chains.
The sprockets used for that following chains would be the same because the typical sprockets in tooth gap form, but unique in tooth thickness (sprocket tooth profile).
4. Calculation of sprocket dimensions
The dimensions of typical sprockets and various common sprockets are calculated as follows. At first, the diameters of sprockets are calculated from the following calculation formulas.
Upcoming, sprocket tooth profile (the shape from the tooth determined by its thickness) is calculated from the following calculation formulas. (The values proven from the following pages had been calculated by these formulas and thought to be the conventional values.)
Calculation formulas for diameters and tooth gap forms Calculation formulas for diameters
Calculation of pitch diameter, tip diameter and caliper diameter
The fundamental dimensions of the sprocket ideal for a chain pitch of one mm are respectively named pitch diameter component, tip diameter factor and caliper diameter element. The respective things for respective numbers of teeth are listed under. If these variables are multiplied by chain pitch, the basic dimensions in the corresponding sprocket could be obtained.
Instance:
Inside the case of 80 (25.40 mm pitch) with 35 teeth Pitch diameter (Dp) ＝ P×Pitch diameter factor
Calculation formulas for tooth gap varieties
As the most rational tooth gap forms by which the stress angle adjustments in response towards the elongation of the smoothly rotated roller chain with the lapse of support time, ANSI specify two forms of tooth profiles: U-type and S-type. Generally, S-type tooth profiles are adopted in accordance with ANSI, and our regular sprockets also have S-tooth profiles.
