Hi Gordon, 

Thanks for the post. 

Ideal iron spin rates are truly player dependent. With that said, there is a very basic window I looked for as a fitter. Typically, I liked to see a 6 iron between 13-16 launch with 5800-6300 rpm of spin. From there, it is +/1 2 degrees of launch and 1,000 rpm of spin. I.e. a 7 iron would be 15-18 launch with 7,000 spin. Of course, this was speed dependent. Individuals with higher speeds often benefited from lower launches and spin, vice versa for individuals with lower ball speeds. 

Honestly, I often fit individuals for irons simply by observing ball flight. It is imperative that golfers feel comfortable with the flight of the ball, regardless of launch conditions. 

Hope this helps. 

Bubba