greek "pi" in cutting speed formula of gear shaper similar to Lorenz LS400
 

dear sirs

can anyone explain why greek *pi* is present in the cutting speed
formula of the gear shaping machine, while the cutter takes a
reciprocatory movement (not a circular movement). this confusion has
been breaking my head for a long time.

formula for cutting speed = pi * stroke length * no. of strokes

looking forward for a quick answer from you

with advanced thanks

Natarajan Ayyavu