The Seiko H357A is a battery-powered quartz analog movement engineered for simplicity, reliability, and compactness. It powers classic three-hand wristwatches with a clean and minimalist design, providing accurate timekeeping with minimal maintenance. The H357A is a favored choice in entry-level and fashion watches, especially where a straightforward analog display without additional complications is desired.
Overview
The H357A delivers time-only functionality, showing hours, minutes, and central seconds. It is powered by a standard silver oxide battery and is well known for its durability, low power consumption, and precision. The movement’s slim profile and moderate diameter make it particularly suitable for smaller case sizes, including many ladies’ and unisex models.
Key Features
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Quartz Precision: Typically accurate to within ±15 seconds per month
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Three-Hand Analog Display: Hour, minute, and seconds hands
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Battery Powered: Uses standard silver oxide batteries such as SR626SW
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Compact Design: Fits small to mid-sized watch cases comfortably
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Low Maintenance: Long battery life and simple servicing
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Hacking Seconds: Seconds hand stops when setting the time, allowing precise synchronization
Technical Specifications
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Caliber: Seiko H357A
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Movement Type: Quartz analog
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Battery Type: SR626SW or equivalent (1.55V silver oxide)
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Battery Life: Approximately 2–3 years, depending on usage
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Accuracy: ±15 seconds/month
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Jewels: 0
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Display Format: Time only (hours, minutes, seconds)
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Hand Hole Sizes:
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Hour: ~1.10 mm
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Minute: ~0.65 mm
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Seconds: ~0.20 mm
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Dimensions:
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Diameter: Approx. 17.0 mm
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Thickness: Approx. 2.5 mm
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Operating Instructions
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Time Setting: Pull the crown out to its single setting position and rotate to adjust hour and minute hands. The seconds hand will stop during adjustment (hacking function), enabling precise time setting.
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Battery Replacement: Replace the battery when the movement stops or the seconds hand skips irregularly, often moving two seconds at a time.
Battery Replacement & Maintenance
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Open the case back with proper watchmaking tools.
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Remove the depleted battery using plastic or non-metallic tweezers to avoid short circuits.
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Insert a fresh SR626SW battery, paying attention to polarity.
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Close the case back securely and verify operation.
Regularly inspect seals and gaskets to maintain water resistance if the watch is rated.
Common Issues
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Watch Stops or Ticks Irregularly: Usually a sign of a weak or dead battery; replace promptly.
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Timekeeping Drift: May be due to battery aging or magnetic interference.
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Moisture Ingress: Check and replace seals if the watch is water-resistant and exposed to moisture.
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Crown or Stem Problems: Avoid excessive force when setting the time to prevent damage.
Applications
The Seiko H357A suits:
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Simple, time-only analog wristwatches
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Fashion watches emphasizing minimalism and elegance
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Small to medium watch cases, including many ladies’ and unisex designs
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Entry-level quartz watches requiring reliable performance
Conclusion
The Seiko H357A is a compact, dependable quartz movement designed for basic analog watches. With its reliable timekeeping, low power consumption, and straightforward operation, it serves as a solid foundation for minimalist wristwatches. Its compact size and ease of maintenance continue to make it a favored choice for watchmakers and consumers seeking elegant and practical time-only watches.
