Pallet Fork
The pallet fork is a small anchor-shaped lever in the escapement. Its two jewelled pallets lock and release the escape wheel in turn, and in doing so it hands a measured push of energy to the balance wheel. That locking and releasing action is what makes a watch tick.
At a glance
- Location
- Escapement, between gear train and balance
- Jewel material
- Usually synthetic ruby (entry and exit pallets)
- Job
- Locks the escape wheel, gives impulse to the balance
The pallet fork is one of the parts that governs how a mechanical watch keeps time. It takes the steady turning force arriving from the gear train and breaks it into measured pulses that match the swing of the balance. That is why it sits at the heart of the escapement, between the energy on one side and the timekeeping oscillation on the other.
What it does
The jewels at each end of the fork take turns stopping and freeing the escape wheel. On every release the wheel advances a little, and over a full back-and-forth swing of the balance it steps forward by one tooth, while the fork hands a small push to the balance wheel. Without that push the balance slowly winds down.
- Locking: the entry or exit jewel halts the wheel, holding the train still for an instant
- Impulse: as the wheel frees, part of its force passes through the fork to the balance
- The tick: the jewels striking the wheel produce the sound you hear
Why its jewels matter
The entry and exit pallets are usually synthetic ruby. A hard, polished surface keeps friction low and lets a calibre run for years without measurable wear. The pallet fork is one piece of a larger subject, the escapement. Understanding how these three parts work together is what explains why a watch ticks at all.
Examples
In any mechanical watch where the seconds hand sweeps in small steps several times a second, those steps are counted by the pallet fork locking and releasing.
View this watchThe Swiss lever escapement, found in almost every modern mechanical wristwatch, uses this same pallet fork logic.
Comparison
The pallet fork and the escape wheel are often confused but do different jobs.
| Option A | Option B | Notes |
|---|---|---|
| Pallet fork | Escape wheel | The fork is the lever that locks, releases and carries impulse to the balance; the escape wheel is the toothed wheel that brings power from the gear train and advances half a tooth per release, one full tooth per back-and-forth swing of the balance. |
Related terms
Watches that show this
Frequently asked questions
What does the pallet fork do?
The pallet fork alternately locks and releases the escape wheel, and on each release it hands a small push to the balance wheel. In doing so it turns the steady force from the gear train into the measured pulses that keep time.
Why are the pallet fork's jewels made of ruby?
The entry and exit pallets are usually synthetic ruby because a hard, smooth surface keeps friction to a minimum. That lets them contact the escape wheel many times a second for years without measurable wear.
Is the pallet fork different from the escape wheel?
Yes, they are separate parts. The pallet fork is the lever that locks, releases and carries impulse to the balance. The escape wheel is the toothed wheel that brings power from the gear train and advances half a tooth each time the fork releases it, one full tooth per back-and-forth swing of the balance. Together they form the escapement.