Timing Pulley Flanges – Pulley School – Class 4: The Basics

Flange codes are very simple. Instead of breaking down each section, we will explain the part number as a whole:

20XL-FA

The initial section of the flange part number will indicate the number of teeth and the pitch of the pulley on which the flange is intended to be used. In our example above, the flange is designed for a 20 tooth, XL pitch pulley.

The last section indicates the material of the flange. In our example above the “FA” indicates “Flange Aluminum”. The same material codes used for pulleys and bar stock are also used for flanges.