Formula Name Pitch Reference Cylinder Tip Diameter Root Diameter Hub Diameter Code PD OD BD MHD Formulas PD=-sin1-PN80 DO=P(0.6+ctg-1N80 ) BD=PD-Dr MHD=P(ctg-1N80 -1)-0.76 Note P= pitch N= number of teeth Dr- roller diameter Checking method for tooth space accuracy: When the ...