F

Fine Time Adjustment - lever to adjust the daily time accurately.

Finished - a watch is said to be finished when the movement has been fitted with a dial, hands, and case.

Five-Minute Repeater - strikes the hours and five minute intervals past the hour. 
                                    (see Repeater)

Flange - The ring that separates the crystal from the dial.

Fly-back hand - In a chronograph there is an additional seconds hand that moves with the seconds hand and can be stopped independently and then made to catch up ("fly-back") with the other constantly moving seconds hand.

Flyback Chronograph - (retour en vol) A chronograph that can be stopped, reset and restarted with a single push of one button. 

In a regular chronograph it would take 3 pushes of 2 different buttons to stop, start and restart.

Push the top button to start

Push the bottom button to reset

Push the top button a second time to restart

A flyback chronograph allows restart timing immediately without the delay of several pushes.
One push of the bottom button accomplishes all of the 3 above functions.

Fob - 

Pocket watches were usually carried inside a vest pocket.  
To make it easer to withdraw the watch a chain was attached to the watch.  The fob was an object attached to the chain making it easier to grasp something to withdraw the watch. The fob was decorative, as well as functional, as the fob would hang outside of the pocket.

Foudroyante - a small dial on a chronograph that is marked 0 - 8. The small hand on the dial completes a sweep every second. This allows you to read the elapsed time to 1/8 of a second.


French Revolutionary Time -

the day was divided into 10 decimal hours. Each hour was divided into 100 minutes and each minute into 100 seconds.  Clocks were constructed with decimal faces.  Time was reckoned from Paris, which is about nine minutes, twenty-one seconds ahead of GMT.  “1” was used as the origin so midnight was ten o'clock. Decimal time originated in 1793 and was abandoned after only two years.

Frequency - the number of vibrations per hour.

Full Rotor - Automatic watches with winding weights (rotors) that travelled 360 degrees in both directions.  Generally more desirable than bumper winds.