Ships from the USA — orders leave within 1–2 business days

Automatic movements, explained

by The Workshop

An automatic (self-winding) movement is a mechanical engine: a coiled mainspring stores energy, a train of gears releases it, and a balance wheel divides it into steady beats. No battery, no electronics.

How it winds itself

A weighted rotor spins with the motion of your wrist and winds the mainspring as you wear the watch. Wear it daily and it simply stays running. Most automatics can also be wound by the crown — useful after a few days off the wrist. A typical power reserve is around 40 hours; if the watch stops, wind it a couple of dozen turns, set the time, and go.

What accuracy to expect

A healthy workhorse automatic commonly runs within roughly −20 to +40 seconds per day, and a well-regulated example much tighter. That is not a quartz watch — a quartz module is accurate to seconds per month — and that difference is the point: you are wearing a running machine, not a circuit. Position, temperature and wind state all nudge the rate slightly. Vintage automatics vary more, depending on age and service history.

Setting and handling

  • Set the time moving the hands forward rather than spinning them backwards at speed.
  • If the watch has a date, avoid changing it via the quickset while the hands are between about 9 pm and 3 am — many calibers engage the date-change mechanism in that window.
  • A screw-down crown must be unscrewed before setting and screwed back down after — it is part of the water-resistance seal.

The hacking and hand-winding questions

"Hacking" means the seconds hand stops while you set the time, letting you sync to a reference clock. "Hand-winding" means the crown can wind the mainspring. Many modern workhorse calibers, such as Seiko's NH35, do both; many older vintage automatics do neither, so check the individual watch.

Servicing

A mechanical movement is serviceable rather than disposable: any competent watchmaker can clean, oil and regulate a common workhorse caliber. Typical service intervals are measured in years — five to seven is a reasonable expectation — or simply when the watch starts running noticeably fast, slow, or short on reserve.