Mechanical Watch Power Source

All antique pocket watches are mechanical watches powered by mainsprings.
They do not use batteries or other power sources like quartz or digital watches.
They generate power as the wound mainspring gradually unwinds.

The time from fully winding the mainspring until it stops is called the power reserve.
For antique pocket watches, the power reserve is usually around 30 hours.
People in the past probably had a routine of winding their watches at a set time once a day.

There are two types of winding for pocket watch mainsprings: hand-winding (crown winding) and key-winding.
I will explain each one, including some useful tips, with videos.

Hand-Winding (Crown Winding)

This method involves winding the mainspring 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.
Key-winding was originally the mainstream, but hand-winding became mainstream around the late 19th century.

How to Wind and How Much Force to Use

1. When winding the mainspring, hold the watch firmly so you do not drop it.
2. Pinch the crown with two fingers and turn it clockwise when viewed from above.
   It also turns in the opposite direction (counterclockwise), but it will spin freely.
3. It does not require much force, so wind it gently and slowly.

As you wind it, you will gradually feel resistance, and once the mainspring is fully wound, it will no longer wind.
Do not force it to wind any further.

Tip for Re-Grasping the Crown

When winding the mainspring, rather than letting go of the crown after turning it and then re-grasping it, it is recommended to turn it counterclockwise while still holding the crown before winding it.

This is because when you let go, a sudden force is applied to a small part called a "pawl" that prevents the mainspring from unwinding, which can cause malfunctions if repeated over the long term.

Check the Video

Based on the above, I will explain it in the video.

Key-Winding

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

Check the Size of the Keyhole and Key

There is a keyhole for inserting the key on the back cover or similar area.

• If there is one hole, that is the keyhole for turning the mainspring.
• If there are two, the one further from the center is the keyhole for turning the mainspring, while the one near the center is for setting the time.

The size of the key is determined by the watch, so use a key that fits that watch.

Direction to Turn the Key

The direction to turn the key varies depending on the watch.
Swiss and American movements are often wound clockwise, while British movements are often wound counterclockwise.

Turn the key slowly; the direction that makes a clicking sound is the winding direction.
It will not turn in the opposite direction, so do not force it.

Check the Video

Based on the above, I will explain it in the video.

Frequently Asked Questions

Should I avoid fully winding the mainspring?

You may sometimes hear that "you should not fully wind the mainspring."
The reason is that fully winding the mainspring creates a large amount of tension, which can put a strain on the mainspring and its parts, potentially causing the mainspring to break or damaging the parts.

In my experience, I don't think you need to worry too much about it, but you should be a little more careful with valuable or old watches that are not running well.
After figuring out how many turns it takes to fully wind the mainspring using your method, try winding it to about 80% of that number.

The Crown Cannot Be Wound or Is Stiff

If the crown cannot be wound, the watch is likely in a state where it is not running even though the mainspring is wound.
If it can be wound but the crown is stiff, there may be a problem with the crown.

The crown is a part that is directly operated by hand and subjected to force, making it prone to breaking.
It is basically a consumable part, so it needs to be replaced if it becomes difficult to wind.
In either case, first consult a shop that can repair watches.

The Mainspring Cannot Be Fully Wound

This is a state where the crown or key cannot be turned in the correct direction to wind the mainspring further.
In most cases, this is caused by a broken mainspring.

Depending on how the mainspring breaks, the watch may still be able to be wound slightly even when the mainspring is broken, and it may run for a shorter time than usual.
In either case, the mainspring needs to be replaced.
Like the crown, the mainspring is a part subjected to force, so it is basically a consumable part.

Mechanical watches with a mechanism called "automatic winding," which automatically winds the mainspring by shaking the watch, do not have a winding stop, but almost no pocket watches have automatic winding mechanisms.