Two Seiko movements power most of our watches: the NH35 automatic and the VK63 meca-quartz. The first winds itself as you wear the watch; the second runs on a battery and drives a chronograph. Here is what sets them apart, so you can choose according to how you live with your watch.
The NH35, a robust automatic
The NH35 is a self-winding mechanical movement: a rotor turns with the movements of your wrist and winds the mainspring. It beats at 21,600 vibrations per hour, holds about 41 hours of power reserve and can also be wound by hand, with the crown. Its seconds hand moves in a continuous sweep and stops when you pull out the crown, so you can set the time to the second.
Like any mechanical movement, it is less accurate than a quartz: Seiko states a rate of −20 to +40 seconds per day. A watch worn every day therefore needs resetting from time to time. In return, there is no battery, and on many of our models you can watch it work through the see-through caseback.
The VK63, a meca-quartz chronograph
The VK63 combines two worlds. The time is kept by a quartz movement powered by a battery: accurate, it needs no winding. The chronograph is driven by a mechanical module: when you start it, its seconds hand sweeps smoothly across the dial, and the reset to zero is instant.
Seiko states an accuracy of ±20 seconds per month. The battery lasts several years; to change it, send us the watch rather than opening the caseback yourself.
Which one to choose?
- The NH35, if you like the idea of a watch that lives on your wrist, with no battery, and you wear it often. It powers the SharpJust, SharpTilus, SharpNaut, SharpMaster, SharpTos and SharpAge, among others.
- The VK63, if you want a chronograph, a watch that keeps time even after a few days in a drawer, and nothing to wind. It powers the SharpTona and the Royal Sharp chronographs.
Both are made for everyday wear, and both are set simply with the crown.
And the other movements in our watches?
The NH05 is a smaller Seiko automatic, for our 31 mm watches. The NH38 and NH70 belong to the same family as the NH35: they power our open and skeleton dials. The NH34 adds a 24-hour hand to follow a second time zone. The SharpDate uses a Miyota 8285 automatic, which shows the day and date, and the Royal Sharp Lady a Seiko VJ24 quartz. To go further, read our guide Automatic, quartz or meca-quartz: what is the difference?
Chosen your movement? Design your watch on Create my own watch, or find answers to common questions in our FAQ.
