When is it time to service
a mechanical watch?

01 · Why it's neededThe oils dry out. The parts wear.

A mechanical watch isn't self-sufficient forever. Inside it flow specialized lubricants — oils for pivots, greases for gear teeth, specific products for the escapement — that let 150+ components move with minimal friction. Over time, heat, air exposure, and temperature cycles cause these oils to dry out, oxidize or migrate away from the surfaces they were applied to.

When lubricants fail, friction increases. The balance wheel oscillates with less energy — amplitude drops. The gear train works harder — wear accelerates. The escapement doesn't receive the right impulse — rate becomes unstable. If left too long, metal parts run dry against each other: an overhaul that would have cost €200 becomes one requiring replacement parts costing €500-800.

The industry rule of thumb is 5-7 years for a standard mechanical movement in good operating conditions. That's not an absolute deadline — it's a window. A watch worn rarely and stored well can wait 8-9 years; one worn daily in a dusty or humid environment needs attention sooner. WatchScope gives you the tools to know where you are in that window.

02 · The signalsWhen the watch is asking for help.

The signs of a watch approaching service are often subtle and gradual — they don't all arrive at once, usually one at a time. Learn to recognize them:

The signals don't all show at once: usually amplitude drops first, then power reserve, then rate becomes unstable. Unusual sounds are last — and indicate mechanical damage is already underway. Don't wait to hear them.

03 · How oftenThe right interval depends on the watch.

There's no single answer that applies to all. The service interval depends on the movement type, intensity of use and environmental conditions. A guide:

• Standard mechanical movement (ETA, Sellita, Miyota, Valjoux): every 5-7 years. Covers the vast majority of quality modern mechanical watches.
• Mechanical chronograph: every 3-5 years. More moving parts than a simple automatic; the coupling mechanism and chronograph columns wear faster.
• Vintage watch (pre-1990): every 3-5 years. Period materials (oils, gaskets, alloys) degrade faster than their modern equivalents.
• ISO 6425-certified dive watch: every 2-3 years. Water-resistance gaskets must be tested and replaced regularly; the mechanical overhaul is done at the same time.

04 · WatchScopeAmplitude as the oil indicator.

Among all the parameters WatchScope measures, amplitude is the most sensitive to lubricant decline. Here's why: as oils dry out, friction on the balance wheel pivots increases. The balance wheel receives less energy from the gear train with each oscillation — and swings less. Amplitude drops.

This decline is slow and progressive — it doesn't happen overnight. A freshly serviced watch might start at 280°; after 3 years it might be at 255°; after 6 years at 215°. WatchScope lets you track this curve over time, rather than discovering the problem only when the watch stops. How to use it:

• Baseline after service: run a WatchScope test in the days after the overhaul and note the reference amplitude (typically 260-290°). This is your starting point.
• Test every 6-12 months: repeat the test under the same conditions (same wind level, same position). Log the results in WatchScope's watch history.
• Interpret the trend: a drop of 20-30° from baseline is normal after 2-3 years. A 50-60° drop means service is approaching. Below 200° amplitude is urgent.

05 · The overhaulWhat happens in the workshop.

Understanding what happens during a service reduces anxiety and helps you evaluate whether the watchmaker's quote is justified. A full service of a mechanical movement includes:

• Full disassembly: every single component is separated — balance wheel, hairspring, wheels, pinions, plate, bridges — and catalogued. A medium-complexity movement has 150-200 parts.
• Ultrasonic cleaning: components are immersed in specific solvents and ultrasonically agitated to remove old oils, oxides and residues. No mechanical tool touches the finished surfaces.
• Inspection and replacement: every part is examined under a microscope. Worn balance springs, chipped teeth, cracked jewels are replaced. The mainspring is often changed.
• Lubrication and reassembly: lubricants are applied with surgical precision — too much is as damaging as too little. The movement is reassembled and regulated on the bench.
• Final testing: the movement is tested for at least 24-48 hours in multiple positions, checking rate, amplitude and beat error. For watches with guaranteed water resistance, pneumatic pressure testing.