4021X sprocket is a "X series" weld on sprocket that is made to ANSI standards. The 40X21 sprocket is 21 tooth sprocket for #40 ANSI roller chain. Any "X series" weld on hub will work with our 4021X sprocket. This sprocket is manufactured from 1045 carbon steel and has hardened teeth for wear resistance.
4021X Sprocket Dimensions
ANSI Chain Size:40
Pitch Diameter (dp):3.355''
Outside Diameter (de):3.618''
Sprocket Thickness (B1):0.284''
Hardened Teeth:Yes (HRC 40-50)
Type Of Finish:Black Oxide
It's recommended to use Low Hydrogen Electrodes for welding weld on sprockets & hubs. Below is a diagram showing the location to weld on small vs large diameter sprockets.