Seiko - 5 Sports Speed-Timer 'Bullhead' - No reserve price - 6138-0040 - Men - 1977

Now available at auction from Second Vintage

This sought-after JDM Bullhead chronograph presents a compelling configuration of the celebrated Seiko 6138-0040. Characterized by its distinctive top-mounted crown and pushers, this specific example features the collector-favorite Japan Domestic Market '5 Sports Speed-Timer' dial with an English and Japanese Kanji day wheel, offering immense vintage appeal and striking visual presence.

Brand: Seiko
Model: 5 Sports Speed-Timer 'Bullhead'
Reference Number: 6138-0040
Serial Number: 703945
Movement: Automatic chronograph, Caliber 6138B
Dial: Brown with gold-tone subdials
Case Size: 44 mm (excluding the crown)
Case Material: Stainless steel
Production Year: 1977
Condition: Good vintage condition. Timegrapher: -14-18s/day, performing remarkably well.

Dial and Hands
The brown main dial features a vertical day-date display at 6 o'clock in both English and Japanese Kanji, flanked by gold-tone subdials for the 30-minute register at 3 o'clock and the 12-hour register at 9 o'clock. The main dial surface appears well-preserved with clear printing, while the gold-tone subdials exhibit noticeable spotting and patina that add distinct vintage character. The luminous plots show expected aging. Time is indicated by white hour and minute hands containing aged lume, which display minor surface aging and slight discoloration. An orange central chronograph hand and black subdial hands complete the highly legible layout.

Case and Crystal
The stainless steel case features the distinctive bullhead geometry, retaining its original shape with brushed and polished surfaces remaining visible. Consistent with honest age-related wear, moderate scratches and small dings are present, particularly along the edges and flanks. The prominent unsigned knurled crown is positioned at 12 o'clock, flanked by the two chronograph pushers. The brown tachymeter bezel insert displays significant paint loss, scratches, fading of the brown color, and wear along the outer edge. The flat mineral crystal exhibits scratches and minor edge chips, most notably near the 12 o'clock and 6 o'clock positions.

Movement
Powering the watch is the in-house Seiko Caliber 6138B, an automatic chronograph movement featuring a column wheel, vertical clutch, and quick-set day-date mechanism operating at 21,600 beats per hour. Unlike its predecessor, this caliber allows for manual hand-winding alongside the automatic winding system. The movement presents a generally clean appearance with a visible rotor, bearing engravings that note twenty-one jewels. Minor surface marks and light oxidation are visible on some components. Exhibiting remarkable accuracy and consistency, performing brilliantly for a vintage timepiece. The timegrapher records a rate of -14-18s/day.

Strap
The watch is fitted with its original signed bracelet in the recognizable stainless steel fishbone style. The links and signed Seiko clasp show moderate scratches and scuffs, along with normal stretch expected for its age, remaining period-correct and perfectly suited to the robust case. The bracelet accommodates a maximum wrist size of 17.5cm.

Condition
Good vintage condition. The watch exhibits honest wear consistent with its age, retaining its original shape and distinct visual character. The dial shows notable patina on the subdials, while the case and bezel display moderate scratches, dings, and paint loss. The original bracelet shows expected stretch and scuffing. Supported by the recorded timegrapher result, the movement is performing very strongly.

Dimensions
The case measures 44 mm (excluding the crown).

Remarks
This 5 Sports Speed-Timer offers the sought-after combination of the JDM dial, Kanji day wheel, and the original fishbone bracelet. The distinctive bullhead case geometry and honest vintage patina make this a compelling acquisition for dedicated collectors of Japanese chronographs.

History
The Seiko 6138 series, introduced in the early 1970s, represents a significant chapter in the development of automatic chronographs. Building upon the groundbreaking Caliber 6139, the 6138 added a 12-hour register and the ability to manually wind the movement. The 6138-0040, affectionately known by collectors as the Bullhead due to its top-mounted crown and pushers, was designed to prevent the pushers from catching on clothing or equipment during timing activities. The Japan Domestic Market versions, designated as 5 Sports Speed-Timer models, are particularly prized for their unique dial texts and Kanji day wheels, cementing their status as sought-after vintage timepieces.

Payment and Shipping
Payment must be completed within 1–3 days after purchase.
Your watch will be professionally and securely packaged, then shipped with tracking and insurance for your peace of mind.
We use fast express shipping, with typical delivery within 1–4 business days, depending on the destination.
Please note that vintage watches may show minor signs of wear, aging, or imperfections, which are considered normal for watches of this age.
We kindly ask you to review all photos carefully before bidding. We photograph each watch from multiple angles to provide the most accurate representation possible, and the photos form an important part of the description.
The timegrapher assessment if provided is seen as an indication of the movement’s condition under fully wound testing conditions. As with all vintage watches, results may vary in daily use.
If you have any concerns regarding functionality or defects after delivery, please contact us within 3 days of receiving the watch so we can assist you.
As with all used watches, water resistance is not guaranteed.
If you have any questions, feel free to contact us after the auction ends.

/ Second Vintage

SKU: SEI-SSX-0022