What Powers a CrownCraft Watch?
Every mechanical watch is defined by its movement — the engine that drives the hands, powers the complications, and keeps time. At CrownCraft, we build our watches around Japanese automatic movements from the Seiko Instruments (SII) and TMI families: the NH35A, NH34A, NH38A, and VK63. These are not random choices. Each caliber is selected for its proven reliability, serviceability, and precision.
The NH35A: A Workhorse Movement
The Seiko NH35A is arguably the most trusted automatic movement in the independent watchmaking world. It is a 24-jewel, self-winding caliber that beats at 21,600 vibrations per hour (6 beats per second) and delivers a power reserve of approximately 41 hours. The NH35A features hacking (the seconds hand stops when you pull the crown, allowing precise time setting) and hand-winding capability — two features that were once exclusive to movements costing five times as much.
The NH35A traces its DNA to the legendary Seiko 7S26, which powered millions of Seiko watches worldwide for decades. The NH35 is its modern evolution — same bulletproof reliability, but with the added convenience of hacking and hand-winding. It is the movement inside our CENTRE COURT, DEEPMASTER, and BELMONT models.
The NH34A: True GMT Function
The NH34A is a more specialised caliber designed for GMT watches — timepieces that track two time zones simultaneously. It powers our MERIDIAN-GMT, driving an independent 24-hour hand that can be set separately from the main hours. This is a true GMT function, not a cosmetic feature. For a full comparison of GMT watches in this price range, read our Best Affordable GMT Watches guide.
The NH38A: Open Heart Display
The NH38A shares the same architecture as the NH35A but removes the date complication, creating a cleaner dial layout. We use it in the ROADSTER, where the absence of a date window allows for a larger open-heart aperture — revealing the beating balance wheel through the dial. Learn more about this complication in our Open-Heart Watches Explained guide.
The VK63: Hybrid Chronograph Precision
Not every complication requires a fully mechanical solution. The VK63 is a meca-quartz hybrid by TMI (a Seiko Group company) that combines the accuracy of a quartz oscillator with the mechanical feel of a traditional chronograph. When you press the pushers on our SPEEDWAY chronograph, you feel the satisfying snap of a mechanical cam system. Read our deep dive: What Is a Meca-Quartz Watch?
Why Japanese Movements?
Swiss movements dominate the luxury conversation, but Japanese calibers from the Seiko family offer extreme value-to-performance ratio. An NH35A delivers comparable daily accuracy to entry-level Swiss movements at a fraction of the cost, with the added benefit of being easily serviced by any competent watchmaker worldwide.
This is a deliberate design philosophy at CrownCraft. We invest in the case finishing, the sapphire crystal, the bracelet construction, and the water resistance — knowing that the movement inside is already proven by decades of real-world use.
Caring for Your Automatic Movement
An automatic watch is powered by the motion of your wrist. If you wear your CrownCraft daily, the mainspring stays wound and the watch keeps running. If you leave it unworn for more than 41 hours, it will stop — simply set the time and wear it again, or use the hand-winding crown to restart the movement. For optimal accuracy, we recommend having your watch serviced every 5 to 7 years.
Keep Reading
The Complete Guide to Automatic Watches · Automatic vs Quartz · Best Watches Under €300 · How CrownCraft Watches Are Made