Hackers have been in the news a lot lately.

With many gatherings and classes going online during the spring, “Zoom hacking” became an issue with random strangers popping into private meetings.

Just this week, a large hack affected Twitter with some private information from users being taken.

In the watch world, however, hacking is something far less scary. A watch that “hacks” or that has “hacking seconds” is one in which the seconds hand stops when the crown is pulled out.

Hacking is achieved when pulling the crown out to the setting position causing a lever to come into contact with the balance wheel, in turn, causing it to stop and to be held in position.

Hacking allows the watch to be set to a reference signal, or synchronized with a second timepiece. Pushing in the crown releases the lever, allowing the balance wheel to move freely.

Hack on a Rolex 3035

The hack on a Rolex is a simple thin piece of brass that is attached on the dial side to the detent lever.

When the stem is pulled into the setting position, the hack slides forward and lightly touches the underside of the balance wheel stopping the watch. Simple!

Here is a hack in the run position.


Here is a hack in the setting or “stop” position


Here is the dial side of the watch with a hack attached to the detent lever in the run position.


This watch is in the setting position with the hack engaged.


Hamilton 4992B Pocket Watch with a Hack

The Hamilton 4992B Military Pocket Watch is designed with a hack. It was used in World War II for aviation navigation. The hack was essential in timing for aviation and bombing runs.


Hack Mechanism Attached to Setting
ETA Movement Mechanical Hack

Most ETA mechanical movements come with a hack. It is a simple brass lever that is attached to the clutch wheel. It slides forward to lightly tough the balance wheel when the watch is in the setting position.

Here is a simple sliding hack typical on most ETA movements.


HAPPY ANNIVERSARY! Monday was Mark and Jan’s 35th wedding anniversary!

Mark Sirianni Watch Repair
25 Fraley Street
Kane, Pa. 16735
814-837-9435
814-558-4818 (cell)
watchdoctorpa@gmail.com

CHARLEY PHOTO OF THE WEEK: Charley’s summer vacation so far has included walking, napping and getting brushed.