While the Ref. 6139 may have been Seiko’s first automatic chronograph, it’s safe to say that the “Bullhead” is one of the brand’s true icons.
From the top-mounted pushers and crown, a design that perfectly captures the experimental spirit of the 1970s, to its bold case shape and rich brown tones, few watches embody the decade’s character quite like this one. It might just be the most ‘70s Seiko ever made from the SpeedTimer series.
Today’s example is unworn, preserved in outstanding condition, and accompanied by its original instruction manual, swing tag, and iconic red Seiko 5 Sports box. According to the original owner, he never wore it simply because he loved how it looked, a sentiment any collector can relate to, but that doesn’t mean it isn’t meant to be enjoyed on the wrist.
Despite its bold design, the Bullhead wears comfortably: The curved case hugs the wrist in a way that feels natural and surprisingly balanced.
This is a rare opportunity to acquire an exceptionally well-preserved example of one of Seiko’s most distinctive chronographs, and trust us, it’s even more striking in person.
The watch will be serviced once purchased, please allow 1-2 months for servicing to be completed.
Ships from Tokyo, Japan.
Seiko SpeedTimer 6138-0040 Bullhead
This Bullhead is in immaculate condition. The case remains strong, showing only light storage marks. The dial is the true highlight: Exceptionally clean, with hands that retain their original form. The bezel is beautiful.
The crystal is pristine, with no cracks but only a few light scratches due to storage.
Completing the package, the watch comes with its original instructions manual, swing tag, and box.
BRAND: Seiko
MODEL: 5 Sports SpeedTimer "Bullhead"
REFERENCE: 6138-0040
DIAL: Original black dial
CASE MATERIAL: Stainless Steel
CASE DIMENSIONS: 46 mm Diameter, 15.5mm thickness, 20mm Lug Width
CRYSTAL: Mineral Crystal
CASE BACK: Screw-in Stainless Steel
MOVEMENT: Seiko Automatic Cal. 6138B
Manufacturing date: February 1975
Service History: Unknown
Bracelet/Strap: Original bracelet coded XGA-360

