Determining Tooth Thickness of Various Gear Types (Part III)

In order to determine the tooth size of a gear after taking into account the backlash allowance, you first must determine what the nominal tooth thickness should be. There are three methods for determining this value: chordal tooth thickness measurement, span measurement, and over-pin or ball measurement. For this article, we will discuss measurement over rollers, which is more commonly known as over-pin or ball measurement.