If you’re a mechanical watch enthusiast, you most likely wear your watch primarily because you love the engineering and history behind it. Let’s be totally frank: a $15.00 Casio watch from Walmart is almost certainly a more accurate timepiece than your $1,500 Swiss automatic. But just because you have an obsession with horology doesn’t mean you don’t want your watch to be functional. After all, it’s still a watch, and you probably want to use it.
In that case, it’s important to set some reasonableexpectations. Just how accurate should you expect your mechanical watch to be?I’m about to break things down for you, so you can know what to expect.
Minuscule Parts
The first, most obvious thing to consider is that mechanical watch movements are composed of minuscule parts. The screws and gears are so tiny that watchmakers need special precision tools just to work on them. The springs can be as small in diameter of a human hair. Given this small size, it’s remarkable that mechanical watches are even accurate to the hour, much less to the minute.
To understand why this is the case, consider the amount ofprecision required to manufacture a quality timepiece. Suppose your watch is99.9 percent accurate. That sounds pretty good, right?
Not right at all. A 99.9 percent accurate watch would be offby 1 minute and 27 seconds per day. A 99.99 percent accurate watch will be offby at least 1 second per day. When you think about it that way, it puts thingsin perspective.
Variables to Consider
So, what factors might affect your watch’s accuracy? The first is basic physics, the law of gravity. Depending on the position of your watch, the balance wheel can be more or less effective. And, during the course of everyday use, your watch is going to move around between various positions.
To compensate for this, watches are adjusted for anywherefrom 2 to 8 positions: dial up, grown down, dial down, crown left, crown up,crown right, crown halfway up, and crown halfway down. A 2-position watch willbe adjusted in the first 2 positions, a 4-position watch will be adjusted inthe first 4 positions, and so forth. The more positions the watch has beenadjusted for, the more accurate it will be.
Temperature is another complicating variable. As temperatures rise and fall, all of those tiny watch components will expand and shrink accordingly. And since different materials expand and contract at different rates, this will invariably throw off your accuracy.
Magnetic interference can also throw off your watch’saccuracy. This is particularly true if your hairspring coils inadvertently getmagnetized. If your mechanical watch is suddenly off by 20 or more seconds perday, a watchmaker can run the springs through a demagnetizer to correct thisproblem.
In extreme cases, coils can even get tangled. This typicallyhappens when your watch is subjected to shock, such as a bad drop. In thiscase, the balance wheel can get thrown off kilter, which can severely impactyour watch’s accuracy. This is another problem that a good watchmaker caneasily fix for you.
Finally, your watch may have some mechanical defects.Admittedly, this is rare if you’re buying from a quality manufacturer. But eventhe best watchmakers sometimes produce a dud. If your accuracy is off by morethan the manufacturer’s rating, your best bet is to contact a customer servicerepresentative and get a replacement. Prominent manufacturers care about theirreputations, so they’ll be willing to work with you.
Realistic Expectations
To find an accurate watch, look for one that’s certified bythe ContrôleOfficiel Suisse des Chronomètres (COSC). A certified watch will beaccurate to a bare minimum of +6/-4 seconds per day, and will generally beaccurate to +/-3 seconds per day. A non-certified watch, meanwhile, willtypically be accurate to about +/-5 seconds per day. Even +/-10 seconds per dayis typically considered acceptable, although in that case you’ll want to setyour watch about once a week.
Regular Maintenance
To keep your watch as accurate as possible, make sure thatit’s been properly regulated. This is done by turning a tiny screw, whichadjusts the tension on the spring. A good watchmaker with the right equipmentcan accomplish this task in just a few minutes.
It’s also important to make sure that your watch is properlyadjusted. Adjustment, as opposed to regulation, means ensuring that the balancewheel is properly balanced. This can also be done by a qualified watchmaker.However, it takes a few hours rather than a few minutes, so expect to payhandsomely for the service.
Finally, it’s important to make surethat your watch is properly lubricated. Over time, lubricating oils in yourwatch will break down, which means their performance will suffer. Depending onthe quality of the original lubricants, this will need to be done every 2-3years. At a bare minimum, have your watch re-lubricated every 5 years. Waitinglonger than that can result in premature wear on your parts, requiringexpensive replacements.
