Glossary · Regulation
Endshake
Permitted axial movement of an arbor between its bearing limits; distinct from sideways bearing clearance.
Explanation
Endshake is freedom along an arbor's axis, not the lateral clearance between a pivot and its bearing hole. Some axial freedom is needed to avoid binding as an assembled train turns. Too little can restrict motion, while excessive freedom can disturb working relationships. The appropriate amount depends on the part and construction; there is no single clearance that can safely be prescribed for every wheel and balance.
Hodinkee's Watch 101 describes endshake as vertical play of a pivot in a jewel hole, where vertical follows the arbor in the movement drawing rather than the orientation of the watch in a room. A still photograph cannot measure that play. During service a specialist examines the actual assembly and its bearing limits, including endstones where fitted. Record a measured value only with method and component identity; do not infer it from low amplitude or a stopping symptom alone.
Sources & references
- https://www.hodinkee.com/watch101/endshake
- de Carle, D., Practical Watch Repairing — technical further reading; exact procedures require calibre documentation
Where sources disagree, the disagreement is stated rather than resolved silently.
What to record
- Name the arbor and the bearing arrangement.
- Distinguish axial freedom from side clearance.
- Keep measured condition separate from a photograph's appearance.
Do not press jewels or bend bridges to alter clearance; treatment requires measurement and suitable tools.