Description
SEIKO vintage mechanical watch
MADE IN JAPAN
“Seiko” (精工) is a Japanese word meaning “precision,” “exquisite workmanship,” or “refined craftsmanship.”
It comes from the characters:
- 精 (sei) – fine, precise, refined
- 工 (ko) – craft, workmanship
Originally, Seiko’s watchmaking division was called Seikosha (精工舎), meaning “House of Precision.”
The name first appeared on a watch dial in 1924, shortened from Seikosha and keeping the core meaning; the company itself was renamed Hattori Seiko in 1983 and Seiko Corporation in 1990.
So the brand name literally ties directly to the idea of precision engineering—which is exactly what the company wanted to be known for in its watches.
About the Business-A Line
The Seiko Business-A was introduced in the late 1960s as the direct successor to the Seikomatic-R — Seiko’s slim, sophisticated dress watch for the emerging Japanese salaried professional class.
By the late 1960s, the Seikomatic-R had already established the template: a slim 83-series movement, day-date complication, clean round case, and the understated elegance of a watch that disappeared under a shirt cuff. The Business-A carried this formula forward with the refined 83-series calibers — automatic movements with Diashock shock protection running at 18,000 bph — while updating the aesthetic to match the tastes of the new decade.
The name was deliberately straightforward: “Business” for the white-collar audience it served, “A” for automatic. No clever portmanteau — just a clear statement of purpose for the dress watch of Japan’s post-war business generation.
The 83-series calibers powering the Business-A were a genuine step up from entry-level Seiko offerings: 27 to 30 jewels when most mid-market automatics offered 17–21, with Diashock protecting the balance staff through decades of daily wear. The day-date at 3 o’clock added practical utility without cluttering the dial, with a quickset date; the day is set by cycling the hands past midnight.
The Business-A occupies the sweet spot between the Seiko 5 (entry-level) and the King Seiko (luxury) — offering genuine professional-grade horology at a price the secondary market hasn’t fully caught up with. Many were sold on period expansion bracelets, and plenty have since been swapped for straps or lost links along the way.
About This Watch
This is a Seiko Business-A day-date, reference 8346-8000, powered by the automatic caliber 8346A — a 27-jewel Suwa Seikosha movement with Seiko’s Diashock shock protection, running at 18,000 bph and offering manual hand-winding alongside automatic winding. Its case-back serial number, 7101017, dates its manufacture to January 1967, placing it right at the start of the Business-A’s production run.
The dial is a bright silver linen finish — fine vertical brushing rather than a radial sunburst — with applied faceted baton markers and a framed day-date aperture at 3 o’clock, the day shown in English with Sunday picked out in red and Saturday in blue. It sits in a 36 mm stainless steel case (excluding crown) with a polished bezel and sharply faceted lugs, fitted on a vintage brown leather strap. The dial is coded 8346-8021T while the case-back reads 8346-8000; Seiko catalogued dial designs and case designs under separate numbers, so the two are not expected to match — it is the shared 8346 caliber prefix that confirms the pairing.
Technical Specifications
- Brand: Seiko
- Line: Business-A
- Reference Number: 8346-8000
- Movement: Automatic with hand-winding, caliber 8346A, 27 jewels, 18,000 bph
- Serial Number: 7101017
- Production Date: January 1967
- Case Material: Stainless steel
- Case Diameter: Approx. 36 mm (excluding crown)
- Dial: Silver linen with applied faceted baton markers
- Crystal: Acrylic
- Case-back: Stainless steel, engraved “Stainless Steel — Water Proof”
- Country of Manufacture: Japan
Condition Report
The silver linen dial is bright and legible, showing light scattered age speckling toward the outer edge; the applied markers and flat baton hands are intact and retain strong luster. The stainless steel case is solid, the polished bezel and faceted lugs keeping good definition, with light surface marks and a few small nicks along the bezel edge and lug tips consistent with age. The acrylic crystal is clear, with some scratches. The movement runs, the date quicksets and the day advances correctly — the day is set by cycling the hands past midnight. Fitted on a vintage brown leather strap with an unsigned steel buckle.
This watch has recently been serviced by a professional watchmaker and keeps good time.
Comes complete with new padded leather strap.
*Note: Vintage leather straps are included as-is and may show wear consistent with age.
Opt for new Seiko lug width matched padded leather strap – we match the strap to this watch’s lug width, so there is nothing for you to measure.
Just pick a padded leather strap for Seiko from the options at the top of the page.
This watch ships from 🇺🇦 Ukraine with tracking number
Why Collectors Want This Watch Today
The Business-A is one of the most quietly rewarding corners of vintage Seiko collecting: genuine 1960s Japanese watchmaking — a 27-jewel automatic with day-date and Diashock — at a fraction of the price its King Seiko and Grand Seiko contemporaries command. As the direct heir to the Seikomatic-R, it carries the same understated dress-watch character that defined Seiko’s approach to the salaryman market.
At 36 mm the 8346-8000 is a classic mid-1960s dress size that still wears comfortably today, and a January 1967 serial places this one right at the beginning of the line’s short 1967–1969 run. The fine vertical linen finish gives the dial a texture that shifts as the light moves, rather than the flat look of a plain silver dial. For a collector who wants a period-correct Japanese automatic to actually wear rather than store, the Business-A remains a genuinely undervalued entry point.
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We guarantee the item you receive looks and works exactly as advertised — or your money back.
Seiko lug-width matched leather straps — 18 / 19 / 20 mm
About the watch factory
Seiko Group Corporation (セイコーグループ株式会社, Seikō Gurūpu kabushiki gaisha), commonly known as Seiko, is a Japanese maker of watches, clocks, electronic devices, and semiconductors. Founded in 1881 by Kintarō Hattori in Tokyo, Seiko introduced the world’s first commercial quartz wristwatch in 1969.
Seiko is widely known for its wristwatches. Seiko is one of the few watch companies that is fully vertically integrated. Seiko is able to design and develop all the components of a watch, as well as assemble, adjust, inspect and ship them in-house. Seiko’s mechanical watches consist of approximately 200 parts, and the company has the technology and production facilities to design and manufacture all of these parts internally.
Seiko offers one of the widest ranges of watch technologies in the world—quartz, kinetic, solar, mechanical, and Spring Drive—spanning everything from affordable everyday pieces to six-figure haute horlogerie. Over the decades it has launched multiple global brands, including Lorus, Pulsar, and Alba, while elevating its prestige through innovations like Spring Drive, which helped push Seiko into higher-end territory. In 2017, Grand Seiko was spun off into its own standalone luxury brand, while Credor remains part of Seiko’s own lineup, sold primarily in Japan. Seiko’s own global lineup now includes Grand Seiko, King Seiko, Prospex, Astron, Presage, and Seiko 5 Sports.
Among Seiko’s key lines, Seiko 5 (born in 1963) is the gateway mechanical series known for durability and value; Lord Matic defined 1970s style with faceted crystals and colorful dials; Astron remains Seiko’s flagship GPS-solar tech line; Presage focuses on traditional mechanical craftsmanship with enamel and urushi dials; and Prospex delivers professional-grade dive, field, and pilot watches often embraced by enthusiasts. At the top end, Grand Seiko emphasizes precision, Zaratsu polished design, and movements like Spring Drive, while King Seiko—revived in the 2020s—brings back sharp, elegant 1960s styling with modern calibres.
Finally, Credor represents Seiko’s pinnacle of artisanal watchmaking, producing low-volume pieces in precious metals and showcasing Japanese decorative arts and haute complications from the Micro Artist Studio. Beyond watches, Seiko has also produced various electronic devices and, historically, jewelry and eyewear—though those divisions have since shifted to other companies.
