The Approx dimensions of a 1/2×21 Chain Sprocket are typically as follows:

Sprocket Diameter: 91.5 mm

Boss Diameter: 68 mm

Teeth Pitch:1/2″

Attach Chain:08B-2

Number Of Teeth: 21 Nos.

The Approx dimensions of a 1/2×24 Chain Sprocket are typically as follows:

Sprocket Diameter: 103.6 mm

Boss Diameter: 80 mm

Teeth Pitch:1/2″

Attach Chain:08B-2

Number Of Teeth: 24 Nos.

The Approx dimensions of a 1/2×27 Chain Sprocket are typically as follows:

Sprocket Diameter: 115.7 mm

Boss Diameter: 94 mm

Teeth Pitch:1/2″

Attach Chain:08B-2

Number Of Teeth: 27 Nos.

The Approx dimensions of a 1/2×28 Chain Sprocket are typically as follows:

Sprocket Diameter: 119.7 mm

Boss Diameter: 97 mm

Teeth Pitch:1/2″

Attach Chain:08B-2

Number Of Teeth: 28 Nos.