Seiko 2516B - Parts List
Seiko 2516B – Technical Guide
The Seiko 2516B is a manual-winding mechanical movement designed for ladies' wristwatches, introduced as part of Seiko’s compact 25xx series in the late 1960s to early 1970s. It is a refined evolution of the 2516A, offering a date complication while maintaining the slim profile and simplicity required for elegant, smaller watches. Built with reliability and serviceability in mind, the 2516B is a compact movement that performs well for its size and age.
1. Technical Specifications
| Specification | Detail |
|---|---|
| Caliber Number | Seiko 2516B |
| Movement Type | Mechanical – Manual winding |
| Functions | Hour, Minute, Date |
| Jewels | 17 |
| Beat Rate | 21,600 vibrations/hour (6 beats/sec) |
| Power Reserve | ~40 hours |
| Manual Winding | Yes |
| Automatic Winding | No |
| Hacking Seconds | No |
| Quickset Date | No (advance via time cycling) |
| Calendar | Date (non-quickset) |
| Movement Diameter | ~17 mm (~7¾ lignes) |
| Height | ~3.2 mm |
| Shock Protection | Yes (Diashock on balance staff) |
2. Key Features
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Two-hand display (hour and minute), with date at 3 o’clock
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Manual-wind only design — no rotor or automatic winding
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Compact and slim profile, ideal for vintage ladies' dress watches
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Non-quickset date mechanism (requires advancing the hands past midnight)
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High beat rate (21,600 bph) for improved accuracy and smoother hand motion
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17-jewel architecture ensures durability and reduced pivot wear
3. Calendar Operation
How to Set the Date:
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Pull the crown to the time-setting position.
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Rotate the hands forward past 12:00 AM until the date changes.
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Repeat this 24-hour cycle to reach the desired date.
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Push crown back in when finished.
⚠️ Avoid rotating the hands backward across midnight repeatedly, as this may damage the date jumper and driving gear.
4. Movement Construction
Dial Side:
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Date disc, date jumper, and calendar driving wheel
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Cannon pinion, hour wheel, minute wheel
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Setting system (clutch, stem, and sliding pinion)
Train Side (Back Plate):
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Mainspring barrel
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Gear train (center, third, fourth, and escape wheels)
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Pallet fork and balance assembly
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Manual winding mechanism (crown wheel, ratchet wheel, click, click spring)
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Balance with Diashock protection
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Fine regulator for timing adjustment
The layout is mechanically simple, optimized for compact space and easy servicing.
5. Servicing Guidelines
Recommended Interval:
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Every 4–6 years, or sooner if timekeeping is poor
Full Service Procedure:
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Carefully disassemble the entire movement
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Ultrasonic clean all metal components; hand-clean the balance/hairspring
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Inspect the pivots, jewels, and mainspring
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Lubricate key points: train pivots, escape teeth, pallet stones, calendar parts
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Reassemble and check hand tension and date alignment
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Regulate to ±20–30 sec/day using a timing machine
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Verify amplitude (~250°+ when fully wound is ideal)
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