Basic watchmaking tips - Spotting wear

It takes a fair bit to surprise me anymore. I'm actually more surprised when I get a watch in that doesn't have parts that look like the samples I've shown!

I wanted to add a couple of other things to watch out for specifically - there are many but seeing a damaged barrel this week reminded me to add this one. So even when dirty, you can see there are some shiny spots around the hole in the barrel drum here:



This is a different barrel, but after cleaning you can see all kinds of damage around the hole:



You rarely see this damage on corresponding hole in the barrel lid, because this is damage caused by a watchmaker, rather than wear. This is some watchmaker making a very ham fisted attempt at installing the barrel arbor, and in the process the hardened steel arbor has caused damage to the soft brass of the mainspring barrel. The damage here can cause a lot of problems with lost balance amplitude and erratic running, because when the mainspring unwinds, the barrel spins around that arbor. If there are burrs here it's going to cause added drag. This damage can be repaired (cleaned up) to a certain extent, but if it's really bad, a new barrel drum is needed.

Another example of watchmaker induced damage to be aware of is on the winding stem:



In this case someone has used a pin vise to hold onto the stem, and they clamped it on the round pilot diameter, rather than on the flats of the stem. This has raised burrs that can act as a reamer on soft brass parts, like the main plate or barrel bridge. So care needs to be taken when dealing with watch parts, because they are often easily damaged, and that damage can snowball into other problems.

Cheers, Al

Not really sure what you mean - I take watches apart often that have no signs of wear on internal parts, so wear is not inevitable. If properly maintained, most of the parts inside the watch can last indefinitely. There are some that will fail eventually, like mainsprings that are constantly being flexed, bearings on rotors, etc., but many other parts inside the watch can last indefinitely, even though they would wear out with neglect.

What level of wear is acceptable is a bit subjective, but as I mentioned Omega does have visual standards for what parts can be used again, and what must be replaced. Note that I am referring to parts that are cleaned and put under a microscope, so if what you are looking for is some sort of external indicator that a collector can check, that's really not something I can give you.

Cheers, Al

For the most part, the answer is yes - most of the damage I've shown that is not watchmaker error, is due to lack of service. Although the question "when does a watch need service?" seems like a simple one to answer, it always isn't depending on your perspective. For me a watch needs service when it's in a state when damage is happening if a service isn't done, but not everyone sees it this way. Many people rely on the watch "telling" them when it needs service, but watches are poor communicators when it comes to their own needs. Some make the decisions based on pure economics, rather than with any "mechanical sympathy" about what is going on inside the watch. So everyone has their own way of dealing with this, and my aim is to simply provide information for people to understand what's going on so they can make informed decisions. If they want to keep doing what they are doing, it's fine with me...not my watch so as I've said before, if they want to smash it with a hammer, go for it.

Now some of the examples I've shown above are not due to lack of lubrication, because in some cases those specific spots don't get lubricated. But sometimes lack of lubrication being renewed in one area, can have an affect in another. So for the two photos of the damaged teeth for the winding and sliding pinions on the previous page, if the cannon pinion is very tight from the grease drying out over time, this will require more force to turn it to adjust the time on the watch, leading to damage of the teeth on the sliding pinion. Lack of proper lubrication of the winding system can cause the wear seen on the teeth of the winding pinion again due to increased loads.


All watch movements are a series of design compromises, and some work out better than others. So movements will have weak spots, and sometimes even regular servicing will not prevent wear in those spots. But generally speaking, regular service can make replacement of major parts an uncommon thing, even after decades of use.


Sort of - better engineering can mean fewer "weak spots" certainly. The finishing (most people refer to decoration when they use this term) isn't really important in terms of lifespan of parts, but what I would call functional finishing is. This is the level of finish on the actual working surfaces of the parts, and how that finish is accomplished. How well are the pivots finished, and is that achieved through traditional burnishing or just through polishing. Polishing produces a high finish, but burnishing produces a better finish in many cases, and also a harder pivot that is more resistant to wear.

So when a maker applies some circular graining finish to a train wheel, or they bevel the spokes of the wheel, those things are higher quality finishes for sure, but they have zero impact on actual performance. For example this is a Patek Cal. 16-250 I serviced and you can clearly see the circular graining and bevels on the spokes of the wheel:



Same on this vintage IWC Cal. 83:



But that doesn't reflect how durable or accurately made these parts are - this is just decoration. Note that the underside of the wheel is not grained or beveled, so only the side that is visible is treated this way. The things that make a part like a train wheel truly of higher quality in a functional sense are things that would have to be measured, not just observed by looking at it.

BTW to be clear some very high end Pateks are worked over "by hand" but having been through their factory I can tell you their production is largely like any other shop - plenty of automation involved, including CNC machines producing parts and even running unattended overnight...

Cheers, Al

These informative threads are fantastic and make this such a great place to visit every day. Huge thank you Al for putting the time to show visually and explain in depth so we can learn in the process.

I understand and agree with everything you've said here.

I suspect for many who buy and sell multiple vintage watches there is an element of "musical chairs". They buy an old watch that is keeping decent time, they wear it occasionally for a time, then hope to sell it before it stops telling time. A watch could get re-sold many times without being serviced and each of them just hopes it keeps 'telling time' long enough for them to sell it for what they paid (or some expected mark-up).

Anyhow, not looking for a comment on this tangent as it is in no way the intention of your excellent thread. Thanks again for sharing!

The watch companies often do this themselves. When you take your car in to the dealer, they sometimes do some "hidden recalls" that were not serious enough to warrant sending you a letter to bring the car in right away - when you send your watch in to the service center, they will often replace parts that are problematic with upgraded parts in the same way. For example Omega publishes (to those who have access) lists of mandatory upgrades that should be done at service.

Improvements are being made even on movements that are long out of production, so this is an ongoing process.

Cheers, Al