It is understood to be at the standard pitch diameter unless otherwise specified.

The ratio of the number of teeth to the pitch diameter.

Ratio of the number of teeth to the pitch diameter.

Ratio of the number of teeth to the standard pitch diameter in inches.

As a result, the term module is usually understood to mean the pitch diameter in millimeters divided by the number of teeth.

Calculating pitch diameter is an engineering task and is beyond the scope of this article.

The pitch diameter is indicated as Dp in the figure shown above.

There are several methods that are used to measure the pitch diameter.

Another way to think of pitch diameter is "the diameter on which male and female should meet".

It was during this era that more complicated analyses made clear the importance of variables such as pitch diameter and surface finish.