Seiko Bullhead Chronograph Automatic 6138-0040 Vintage Watch

The watch has the original bezel, dial, hands, crown, pushers, crystal, and bracelet. The crystal has minimal scratches as shown in the photos. The photos are of this watch.

Please note the condition of the watch in the photos. The 6138 movement was developed by Suwa Seikosha, a branch of the Seiko Corporation, as evidenced by the Suwa logo located on the dial at the 6 oclock position. [6] Although touted as the successor of the 6139 movement, both were manufactured until 1979. The significance of both these movements to Seikos history cannot be stated enough, as these gave them the honour of creating the worlds first automatic chronograph movement that features a column wheel and a vertical coupling mechanism. There were also 2 versions of the 6138 movement; 6138A with 21 jewels, and 6138B with 23 jewels.

Both versions were classified as 2 register chronographs, equipped with a manual wind day/date indicator. The specifications for both versions are a height of 7.9mm and a movement diameter of 27.4mm, allowing them to accurately measure up to of a second, or 21,600 beats per hour.

Seiko successfully mass-produced the layout for the column wheel and the vertical coupling mechanism, which later on became mainstream, and was adapted by Rolex for the development of the in-house movement that they would use on the Daytona. This would come about some 3 decades later, a testament to the innovative advancements offered by the Seiko brand to watchmakers the world over. The 2 subdials for the Seiko Bullhead feature a 30-minute and 12-hour register, as well as a 60-second sweep. (Please note this information is referenced from thespringbar. The item "Seiko Bullhead Chronograph Automatic 6138-0040 Vintage Watch" is in sale since Tuesday, September 1, 2020.

This item is in the category "Jewelry & Watches\Watches, Parts & Accessories\Watches\Wristwatches". The seller is "stelvio996" and is located in Mechanicsville, Virginia. This item can be shipped worldwide.

• Brand: Seiko
• Type: Wristwatch
• Model: Seiko 6138
• Features: Chronograph
• Display: Analog
• Band Material: Stainless Steel
• Customized: No
• Style: vintage
• Dial Style: 12-Hour Dial
• Dial Color: Brown
• Age Group: Adult
• Number of Jewels: 21 Jewels
• Chronograph Type: Chronograph
• Watch Shape: Round
• Department: Men
• Year Manufactured: 1977
• Country/Region of Manufacture: Japan
• Case Material: Stainless Steel
• Movement: Mechanical (Automatic)
• Water Resistance: Not Water Resistant
• Case Color: Silver
• Band Color: Silver
• Gender: Men's
• Reference Number: 6138-0040
• Band Type: Bracelet