Seiko 5 Automatic Ref. 5126-7000 (Daini Factory)
Sport-Dress Tool Watch · Seiko (Daini Seikosha division), Japanese luxury-to-consumer manufacturer known for rugged reliability.
Period: Late 1960s Space Age / Functionalist Modern (Circa 1968-1969). Characterized by its cushion-shaped 'C-case' and futuristic block indices.
Type
Sport-Dress Tool Watch
Brand
Seiko (Daini Seikosha division), Japanese luxury-to-consumer manufacturer known for rugged reliability.
Movement
Seiko Caliber 5126; Automatic/Self-winding, 23 jewels, 19,800 bph frequency, approximately 40-hour power reserve. Features a unique push-button date quickset via the crown.
Dimensions
Case diameter: 36mm; Thickness: 11.5mm; Lug-to-lug: 41mm; Lug width: 18mm.
Description
A classic example of the early 'Seiko 5' philosophy: automatic, water resistant, day, date, and recessed crown. This 5126-7000 represents the 'Daini' factory's high-quality output during the late 60s, offering a 23-jewel movement in an era when most Seiko 5s carried 17 or 21 jewels. The silver sunburst dial and cushion case give it a distinctive vintage presence.
Key Features
Daini factory 'Lightning Bolt' logo, 23-jewel movement marking, 4 o'clock recessed crown, and unique thick block indices.
Dial Description
Silver sunburst dial with applied polished block indices, baton hands with black inserts, a day-date window at 3 o'clock, and the Daini Seikosha 'lightning bolt' logo at 6 o'clock.
Case Material
Stainless steel with a combination of brushed top surfaces and polished chamfered edges.
Crystal Type
Box-shaped Hardlex or acrylic crystal (standard for the era) with visible light scratches.
Bezel Details
Integrated fixed stainless steel bezel, polished to a mirror finish.
Crown & Pushers
Recessed crown located at the 4 o'clock position to emphasize the automatic nature of the movement; push-in style with hidden profile.
Bracelet or Strap
Integrated-style three-link stainless steel oyster-style bracelet with brushed finishing and a folding clasp.
Caseback Details
Solid screw-down stainless steel caseback featuring the Seiko logo, reference number 5126-7000, and serial number.
Movement Type
Seiko Caliber 5126; Automatic/Self-winding, 23 jewels, 19,800 bph frequency, approximately 40-hour power reserve. Features a unique push-button date quickset via the crown.
Water Resistance
Originally 30m (Splash resistant), but currently should be considered non-water resistant due to vintage seal degradation.
Origin & Provenance
Japan; manufactured by the Daini factory (indicated by the lightning bolt logo), which competed internally with the Suwa factory.
Age Estimate
Circa 1968-1969 based on the 5126 movement production span and dial markings.
Cultural Significance
Represents the democratization of mechanical excellence, showing how Seiko provided 'high-jewel' count movements to the general public in a durable, stylish package.
Condition Notes
Overall Good condition. The case shows honest wear with minor scuffs; the crystal has surface scratches; the dial remains clean with sharp printing; lume on hands shows minor aging.
Value Estimate
$150 - $350 USD depending on mechanical health. Values are rising for 'Daini' factory collectibles.
Care & Maintenance
Recommended service every 5-7 years; avoid water contact due to aged gaskets; protect from strong magnetic fields; use a soft cloth for cleaning the acrylic crystal.
Similar Watches
Seiko 6119-series 'C-case' models, Omega Constellation 'C-case', and contemporary Tissot PR 516 models.
Interesting Facts
The 5126 movement is part of a specialized family from the Daini factory that was also used in some of the most collectible 'Seiko 5 Sports' divers of the same era.