Vintage Seiko Seikomatic-R 30 Jewels Automatic wristwatch, from August 1966

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.

🕰️ The Seiko Seikomatic line was a flagship series of high-quality automatic watches produced primarily throughout the 1960s. It represented Seiko’s transition into the modern era of self-winding timepieces, and sat at the top of the company’s mainstream automatic ranges.

The Seikomatic Line: The “Business Class” Ancestor

Seikomatic was designed for the “modern business professional” of the 1960s. Its most iconic design choice was the recessed crown at the 4 o’clock position. Because the movement was so efficient at self-winding, Seiko believed the wearer rarely needed to use the crown, so they tucked it away to create a sleek, “crownless” silhouette that wouldn’t snag on shirt cuffs. That crownless styling belongs to the earlier 62-series Seikomatics and the cal. 840 Slimdate. The later 83-series watches like this one moved the crown back to the conventional 3 o’clock position once the movement gained manual hand-winding, so the crown here is a normal, fully accessible one.

• The Name: It’s a portmanteau of “Seiko” and “Automatic.” At the time, automatic winding was a high-tech feature, so Seiko branded these watches to highlight that they didn’t need manual winding.

• The Design Philosophy: Seikomatics were designed for the “New Lifestyle” of the 1960s—aimed at office workers and professionals. Early Seikomatics were known for having no visible crown (tucked away at the 4 o’clock position) to emphasize that the watch was fully automatic and didn’t need to be touched — a detail Seiko dropped on the later 83-series models like this one, which wear a conventional crown at 3 o’clock.

• The “Weekdater”: The most famous Seikomatic is the “Weekdater,” which featured a full day-of-the-week window alongside the date at 3 o’clock. This was a massive status symbol for business people in the ’60s.

The Seiko Seikomatic-R – (produced roughly between 1965 and 1969) is one of the most intellectually interesting lines for vintage Seiko collectors. It was Suwa’s slim-line answer to the thick 62-series automatics that came before it.

Seiko never documented what the “R” stands for. What is documented is the engineering behind it: during this era Seiko was set on making automatic watches thinner, and the 83-series ran a full millimetre thinner than the 62-series it followed.

• The Slim Profile: While earlier “standard” Seikomatics used the 62-series movement (which was thick and “automatic only”), the Seikomatic-R used the 83-series movement. This was an integrated automatic movement designed from the ground up to be slim, allowing the watch to sit comfortably under a business suit cuff.

• The Business Executive Market: The line was specifically marketed to the emerging class of Japanese “salarymen” and executives. It was a step above the “Sportsmatic” (entry-level) but just below the “King Seiko” (luxury).

Historical Significance

The Seikomatic-R represents the peak of the “Suwa” factory’s mid-range production.

• The Internal Rivalry: At the time, Seiko’s two factories (Suwa and Daini) were in a fierce internal competition to produce the best watches. Daini’s answer to it was the “Seikomatic-P” of 1967, built around the 33-jewel cal. 5106A.

• The Precursor to “Business-A”: From late 1967 Seiko began replacing the Seikomatic-R dial name with “Seiko Business-A,” but the two ran side by side and Seikomatic-R watches continued to be assembled into 1969. It makes the “R” branded watches a comparatively narrow window of production.

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DESCRIPTION

This Seiko Seikomatic-R is a definitive “business-class” timepiece from the golden era of Japanese horology. Manufactured in August 1966, this model (8306-9001) represents the pinnacle of Seiko’s mid-60s engineering, blending a slim profile with a high-jewel count movement.
The 8306A movement is a technical marvel of its time, featuring 30 jewels for reduced friction and increased longevity. Unlike the earlier Seikomatics, the 8306A also winds by hand, and the crown sits conventionally at 3 o’clock where it can be reached. The sunburst silver dial, slim tapered hands and applied faceted indices catch the light beautifully, making it an ideal choice for both formal occasions and daily vintage wear.

Product Specifications

• Brand: Seiko
• Model: Seikomatic-R
• Reference: 8306-9001
• Year: August 1966
• Movement: Caliber 8306A Automatic (30 Jewels)
• Case Material: Stainless Steel
• Case Size: ~35mm (excluding crown)
• Dial: Original Silver Sunburst with “Diashock 30 Jewels” branding
• Complications: Day/Date (Quickset Date function)
• Crystal: Acrylic
• Strap: Stainless steel brick-link bracelet

Condition Report

This piece is in very good vintage condition. The dial is clean with one area of oxidation above the calendar window. The case remains sharp with honest signs of wear consistent with its age. The outer case back has been polished over the years and its engraving is now largely worn away; the serial number, 6848817, is still crisply stamped and dates the watch to August 1966.

This watch has recently been serviced by a professional watchmaker and keeps good time.

Comes with vintage stainless steel bracelet* included.

(*)Note: Stock bracelets are often shortened by previous owners and may not fit you(see bracelet size in the product images).
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.

Modes of payment:

• PayPal
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• bitcoin

We guarantee the item you receive looks and works exactly as advertised — or your money back.

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.