GAUGES
Gauge pins
Snap gauges
Thickness gauges
What are gauges used for?
Gauges are control instruments used in watchmaking to quickly and precisely verify the critical dimensions of parts and components. They serve to compare a piece against a predetermined standard dimension, not by providing an exact numerical measurement but by a simple pass or fail judgment.
Function and use
In the watchmaker’s workshop, gauges are notably used to check:
- The diameter and shape of pivots (using pierced gauges),
- The thickness of parts (using thickness gauges),
- Specific clearances or gaps (also using thickness gauges),
- The internal diameter of holes (snap gauges) or bearings (gauge pins),
- As well as other essential standard dimensions critical for assembly and proper function of the movement.
They provide a rapid quality assurance method, allowing verification that parts meet specifications before assembly or during final quality control.
Types of gauges
- Pierced gauges: These tools are small discs with a precisely bored hole. They are used to test the accuracy of the diameter of pivots or cylindrical components.
- Gauge pins (pivots gauges): Precisely machined and polished cylindrical pieces with extremely accurate diameters (usually within 0.0025 mm). They help check the internal diameter of ruby bearings or caps.
- Snap gauges: Like gauge pins, these are precisely machined and polished cylinders typically used to measure the diameter of holes or bores.
- Thickness gauges: Thin blades of various calibrated thicknesses used to accurately assess the thickness or clearance between two parts. They are often supplied as complete sets of graduated blades for precise checking.
Materials and thermal properties
Gauges used in watchmaking are made from special metal alloys, often stainless steel or specially formulated steels with low thermal expansion. This choice is crucial for ensuring dimensional stability even with temperature changes.
The low thermal expansion coefficient of these materials minimizes the risk of deformation caused by ambient heat or handling, ensuring consistent and reliable measurements over time. This feature is particularly important in watchmaking, where extremely tight tolerances prevail, and minor dimensional variations can affect the precision and operation of watches.
Importance in watchmaking
Gauges are essential control tools in the manufacturing, adjustment, and maintenance processes in watchmaking. Thanks to their ease of use, high reliability, and thermal stability, they allow for rapid and precise confirmation that parts comply with required dimensional tolerances. They effectively complement digital or vernier measuring instruments by providing pragmatic, quick qualitative control.