The height of a tooth above the pitch circle is referred to as what?

The height of a tooth above the pitch circle in gear design is termed the addendum. This is a critical parameter in the geometry of gears. The addendum is the radial distance from the pitch circle to the top of the tooth, providing insight into how much material is above the pitch circle that helps in transferring motion between meshing gears.

Understanding the addendum is essential for calculating various aspects of gear performance, including tooth strength and load distribution. It plays a crucial role in defining the overall size and shape of the gear teeth, as well as ensuring that the teeth engage properly with the teeth of another gear without interference.

In contrast, other terms related to gear teeth serve different purposes; for instance, the top root and land do not refer to the height above the pitch circle, and the hunting tooth concept is used in specialized contexts related to gear profile or design specifics and is not relevant to tooth height above the pitch circle.