Description & Specifications
40A21 sprockets are a ANSI standard size that has 21 teeth and works with #40 roller chain. These sprockets are known as a "Type A", which is a hubless roller chain sprocket. Our 40A21 plate sprockets are a durable, high strength sprocket that is manufactured from 1045CD carbon steel. After manufacturing, the teeth are hardened to help minimize wear, then a black oxide finish is applied for corrosion resistance.

40A21 Sprocket Dimensions
- ANSI Chain Size:40
- Bore:5/8''
- Tooth Count:21
- Pitch Diameter (dp):3.355''
- Outside Diameter (de):3.618''
- Sprocket Thickness (B1):0.284''
- Material:1045CD
- Hardened Teeth:Yes (HRC 40-50)
- Type Of Finish:Black Oxide