Glossary · Mechanism
Pitch (gear pitch)
The theoretical circle diameter used to define the spacing of gear teeth.
Explanation
The pitch diameter is the theoretical circle on which gear teeth are sized and spaced; two meshing gears are tangent at their pitch circles. Tooth form and pitch determine how smoothly power passes through the train. Watch gearing uses cycloidal-derived tooth forms rather than the involute forms of larger machinery.
In the object catalogue
Catalogued objects whose own source record mentions “Pitch (gear pitch)”. The quoted line shows where; it is the seller’s or museum’s wording, not independent verification.
