Sprocket Material and Tooth Hardness

[ExDrill]

Can anybody assist me or point me in the direction of some good literature regarding the selection of the hardness that the tooth faces of a sprocket used for roller chain should be?
The Sprockets we are designing are used with ANSI 1/2" #40 Chain if that helps narrow the scope. Id like to engineer the sprockets rather than blow the cost out and exercise my ignorance by hardening them regardless of whether they need to be or not.

 

[DesignerGuy16]

Pick up the a Browning catalog and go through their calculations. Should cover selecting the correct pitch diameter, minimum # teeth, and max hp ratings of many, many setups at different RPM's. I'm sure the other vendors like Martin, SDP-SI have similar information.

James Spisich
Design Engineer, CSWP

 

[ExDrill]

Thankyou for a reply Jspisich, I found in the meantime an interesting and simple formula from manufacturer Martin:
"Hardened teeth on the smaller sprocket of a roller chain drive are recommended if the drive ratio is four to one or greater or if the smaller sprocket has 24 teeth or less and is running at a speed of over 600 R.P.M." Ill go ahead with that until I find something a little more technical.
Cheers

 

[diskullman]

I don't know why you would design a sprocket when so many are available as stock items. Many Chinese import sprockets are hardened as standard, including plate sprockets. I could understand designing your own hub for a standard plate sprocket.

Russell Giuliano