SEIKO Automatic Chronograph 6138-0049 aka "Brown Bullhead". This is SEIKO iconic driver's chronograph from 1970s. Powered by state-of-the-art SEIKO 6138B movement with three distinctive features: SEIKO's proprietary magic lever self-winding mechanism, the classic column wheel, and vertical coupling. Column wheel and vertical coupling ensure precise chronograph operations and highest level of accuracy, respectively.
The SEIKO 6139 and 6138 series are the first automatic chronograph in the world to feature column wheel and vertical coupling mechanism. They set the standard which is followed by the Swiss watch industries 20 years later. The same movement configuration was adopted by Rolex when it made its own in-house movement for Daytona in the year 2000, 30 years after SEIKO released the calibre 6139 and 6138.
Production date: October 1975.
- Width: 43 mm (excludes crown).
- Thickness: 15 mm.
- Lug: 19 mm.
Original dial and hands are pristine. Lume on dial and hands glow very weakly and fade away quickly.
Bezel insert is in good condition.
Original crystal has scratches. Crystal is untouched and unpolished.
Case and case back are untouched and in fair condition. They have some swirlies and scratches from normal wear. Edges, corners, and original factory brush finish are still clearly visible.
Movement, day-date setting mechanism, and chronograph functions are in good working condition. Fully serviced by SEIKO Service Center, Jakarta on October 2011.
Chronograph second hand resets back to approximately +0.2 second from zero (see picture for reference).
All gaskets (crown, 2x pushers, caseback) were replaced with brand new genuine SEIKO gaskets during last service.
Not water-pressure tested. Water resistant is unknown.
Complete with original Z040S "Fishbone" bracelet with a total length for 7 inch (17,8 cm) wrist. Bracelet has scratches and swirlies.
The case is a work of art as you can see in the following pictures of this untouched example. It is more like a sculpture shaped by an artist, rather than an industrial product made by machines. The case is multi-faceted with combination of mirror polished and brushed finished. The surfaces and lines flow in an organic way. As a driver's watch, the case is slightly tilted up at 12:00 o'clock in order to give better legibility for the user when he/she is driving. The caseback curves down so that it will comfortably hug the wrist.
▲ The original Z040S "Fishbone" bracelet, known for its flexibility and comfort. I wonder why SEIKO never makes this type of bracelet again.
Below are some macro shots showing details of bezel insert, dial, and hands. Dial and hands are in pristine condition. Note that in the pictures below you may see some scratches on crystal obscure the dial and hands. I keep the original crystal untouched and unpolished. Use these pictures as guidance when you want to buy a Bullhead. Be careful with non-original parts and re-painted hands. This is a good article to read if you plan to buy a SEIKO 6138-004x Bullhead: How to Buy a SEIKO 6138-0040/0049 "Bullhead", a Collector's Buying Guide.