How to wind the mainspring of a pocket watch

mechanical watch power

All antique pocket watches are mechanical watches powered by mainsprings .
It does not use batteries like quartz watches and digital watches.
Power is generated by unwinding the winding spring little by little.

The time from when the mainspring is fully wound to when it stops is called the power reserve.
Most antique pocket watches have a power reserve of around 30 hours .
In the olden days, it was a routine for people to wind the mainspring of a watch once a day at a fixed time.

There are two ways to wind the mainspring of a pocket watch: manual winding (crown winding) and key winding .
I will explain each of them including a video, including a little trick.

Manual winding (crown winding)



A method in which the mainspring is wound by turning the crown.

The knurled rotating part on the top or right side of the watch is the crown, and pocket watches with this are hand-wound.
Originally, key rolls were the mainstream, but hand rolls became mainstream around the end of the 19th century.

When winding the mainspring, hold the watch firmly so as not to drop it.
Pinch the crown with two fingers and turn it to the right (clockwise) as viewed from above.
It also rotates on the opposite side (counterclockwise), but it is in an idle state.

You don't need a lot of force, so roll gently and slowly.
As you wind the mainspring, you will gradually feel resistance, and when the mainspring is fully wound, you will not be able to wind it any further.
Do not apply excessive force to wind it.

When winding the mainspring, it is better to rotate it backward while holding the crown instead of lifting your finger after turning the crown.
This is because when you let go of the hand, the small parts called the "knob" that prevent the mainspring from reversing are suddenly subjected to force, which can cause failure if repeated over a long period of time.

Based on the above, we will explain in the video.

Key winding

If the watch does not have a crown, it will be key-wound.

There is a keyhole where the key is inserted when the back cover is opened.
If there is one hole, it is the keyhole for turning the mainspring. In the case of two, the one farther from the center is the keyhole for turning the mainspring, and the hole near the center is for setting the time.
The size of the key is determined by the clock, so please use the key that matches the clock.

The direction to turn the key depends on the watch.
Swiss and American machines tend to turn right, and British machines tend to turn left.
If you turn the key slowly and hear a ticking sound, it is the direction to wind up.
It will not turn in the opposite direction, so please do not turn it forcibly.

Based on the above, we will explain in the video.

FAQ

Shouldn't the mainspring be fully wound?

It is sometimes said that it is better not to wind the mainspring all the way.
The reason is that when the mainspring is fully wound, the power of the mainspring is large and the load is applied to the mainspring and parts, which may cause the mainspring to break or the parts to be overloaded.
Based on my experience, I don't think you have to worry about it too much, but you should be a little more careful with precious watches or old watches that don't work well.
After figuring out how many times you need to turn the mainspring completely in your own way, try winding it about 80% of the time.

The crown cannot be wound, the crown is hard

If the crown cannot be wound, there is a high possibility that the mainspring is wound up and the watch does not move.
If you can wind it but the crown is stiff, there may be something wrong with the crown.
The crown is the part of the watch that is most directly moved by hand and subject to force, so it is the most fragile part.
Since it is basically a consumable item, it must be replaced when it becomes difficult to wind.
In either case, first consult a shop that can repair watches.

I can't wind the mainspring

No matter how much you turn the crown or key in the correct direction, the mainspring will not stop winding.
In most cases, this is due to the mainspring breaking.
Depending on how the mainspring is cut, even if the mainspring is cut, the mainspring can be wound a little and it may run for a shorter time than it should.
Either way, you will need to replace the mainspring.
Like the crown, the mainspring is also a part that is subject to load, so it is basically a consumable item.

In the case of a machine that winds the mainspring automatically by shaking the watch, there is no winding stop, but there are almost no self-winding pocket watches.

See our list of pocket watches here