[ROB at RAGE]

We have used #25 chain for years, caculate the force:

Force = torgue/(PichDiameter/2)

Using the stall torgue of the motor. The chain is rated to be operated at a force of (1,250 lbs/ChainPitch) per ANSI Specifications. This means the rating is 312 lbs. for #25. This is a coninous service rating with probably a 2.5 safety factor over what a new cahin can with stand.

If you use too small of a drive sprocket you might have not only have a very high chain force, but bearing problems also.

I personally don't like average ratings given in catalogs. Use the real machine info and you will have reliability.

You can find this kind of useful info as well as a lot of good stuff in the Machinery's Hand Book.

The only draw back to #25 chain is it may need to be tighned more often. Where #35 chain can usually be set and left alone.