A classic vintage Seiko 5 automatic wristwatch featuring a distinctive textured black dial with silver-toned baton markers and matching silver-toned hands. The dial features the iconic SEIKO, 5, and AUTOMATIC branding, along with a practical combined day-and-date display positioned at 3 o’clock.
The watch is powered by a Seiko Caliber 6309 automatic mechanical movement, a self-winding movement from Seiko’s well-known 6309 series. The day display features a bilingual day wheel, with “LUN” appearing for Monday.
The watch is housed in a vintage stainless steel case with a screw-down stainless steel case back. The case back carries the reference 6309-8900 and serial number 313241, providing important identification details for this example.
The watch is fitted with a stainless steel multi-row bracelet with a changed/replacement clasp. The clasp is not represented as the original factory clasp.
This example is presented in vintage pre-owned condition, with signs of age and wear consistent with a vintage mechanical watch.
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Collector’s Note
The Seiko 5 collection has long been associated with practical Japanese automatic watchmaking, combining self-winding mechanical movements with everyday functionality and distinctive period designs.
This vintage Seiko 5 stands out for its textured black dial, silver-toned furniture, day-date complication and Seiko Caliber 6309 automatic movement.
The bilingual day display adds an interesting period detail, with “LUN” appearing for Monday.
The combination of the vintage Seiko case, mechanical movement and black textured dial gives the watch a distinctive vintage character suitable for collectors and enthusiasts of Japanese mechanical watches.
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Specifications
* Brand: Seiko
* Collection: Seiko 5
* Reference: 6309-8900
* Serial Number: 313241
* Movement: Seiko Caliber 6309 Automatic
* Movement Type: Mechanical — Self-Winding
* Dial: Textured Black Dial
* Markers: Silver-Toned Baton Indices
* Hands: Silver-Toned Hands with Sweep Seconds
* Dial Branding: SEIKO + 5 + AUTOMATIC
* Indicators: Day & Date Window at 3 O’clock
* Day Display: Bilingual Day Wheel
* Date Display: Date Window
* Case: Stainless Steel
* Case Back: Screw-Down Stainless Steel Case Back
* Case Diameter: Approx. 36 mm*
* Crown: Original crown position/design*
* Bracelet: Stainless Steel Multi-Row Bracelet
* Clasp: Changed / Replacement Clasp
* Crystal: Mineral Glass*
* Origin: Japan
*Measurements and component specifications are approximate and should be confirmed against the physical watch.
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Case Back
The original stainless steel case back carries the following identification and period markings:
* SEIKO
* Reference: 6309-8900
* Serial Number: 313241
* Stainless Steel Case Markings
* Period Seiko Case-Back Markings
Serial Number
The six-digit serial number 313241 follows Seiko’s historical serial-number format.
The first digit indicates a production year ending in 3, while the second digit indicates January as the production month.
Because Seiko reused year digits across different decades, the serial number alone cannot conclusively establish the exact production decade.
Therefore, the watch should not be dated to a specific decade solely from the serial number without additional supporting evidence.
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Movement
The watch is powered by the Seiko Caliber 6309 automatic mechanical movement.
* Caliber: Seiko 6309
* Type: Automatic / Self-Winding Mechanical
* Jewels: 17 Jewels*
* Beat Rate: Approximately 21,600 vibrations per hour*
* Function: Timekeeping + Day/Date
The movement is wound automatically through normal wrist movement. As with other vintage mechanical movements, performance depends on condition, lubrication and service history.
*Specifications should be verified against the actual movement if the movement has not been inspected.
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Dial
The watch features a distinctive textured black vintage dial with:
* Black textured dial surface
* Silver-toned baton markers
* Matching silver-toned hands
* Sweep seconds hand
* SEIKO branding
* Seiko 5 logo
* AUTOMATIC marking
* Day-date display at 3 o’clock
The textured dial gives the watch a strong period appearance while maintaining a clean and practical layout.
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Day-Date Function
The watch features a combined day and date display at 3 o’clock.
The day wheel includes bilingual day indications, with “LUN” representing Monday.
This period-style bilingual calendar adds an additional characteristic detail to the watch.
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Bracelet & Clasp
The watch is fitted with a stainless steel multi-row bracelet.
Clasp Disclosure
The clasp has been changed/replaced and is not represented as the original factory clasp.
This detail is disclosed for transparency and should be considered when evaluating the overall originality of the watch.
The bracelet and clasp may show signs of age and previous use. Please inspect the product photographs carefully for the condition of the links, pins, clasp and bracelet fit.
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Condition
Vintage Pre-Owned Condition
The watch is presented in vintage pre-owned condition.
It retains its vintage Seiko:
* Case
* Dial
* Automatic mechanical movement
* Case back
* Stainless steel bracelet
The case, crystal, dial and bracelet may show signs of age, light scratches, surface marks and general patina consistent with a vintage mechanical watch.
The clasp has been changed/replaced and is not represented as the original factory clasp.
The mechanical movement is currently running and keeping time; however, vintage mechanical watches can vary in accuracy depending on their service history and internal condition.
Please refer carefully to all product photographs, as they form an important part of the condition description.
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Why You’ll Love It
* Classic vintage Seiko 5 automatic design
* Distinctive textured black dial
* Silver-toned baton markers
* Matching silver-toned hands
* Original Seiko Caliber 6309 automatic movement
* Practical day and date display at 3 o’clock
* Bilingual day wheel featuring “LUN”
* Vintage stainless steel case
* Screw-down stainless steel case back
* Reference 6309-8900
* Serial number 313241
* Stainless steel multi-row bracelet
* Changed/replacement clasp clearly disclosed
* Distinctive Japanese vintage mechanical character
* A characterful addition to a vintage Seiko collection
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Important Note
Due to the age and nature of vintage automatic mechanical movements, timekeeping performance may vary and may not meet the accuracy standards of modern quartz watches.
The movement should ideally be inspected and serviced by a qualified watchmaker if its recent service history is unknown. Vintage mechanical movements can require periodic servicing to maintain stable performance.
The watch is currently running and keeping time, but this should not be interpreted as a guarantee of future accuracy or service condition.
Any original water-resistance specifications or markings should not be interpreted as a guarantee of present-day water resistance. Gaskets, seals, crystal, crown and case-back components naturally deteriorate with age.
Unless specifically stated otherwise, this vintage watch has not been pressure-tested and should not be assumed to be water-resistant. Swimming, bathing and diving are not recommended.
The bracelet should also be inspected for normal vintage wear, including link condition, pin condition, bracelet stretch and clasp security.
The clasp has been changed/replaced and is not represented as the original factory clasp.
All measurements are approximate. Please examine all product photographs carefully before purchase, as photographs form an important part of the condition description.
