SOLD – Seiko 6138-7000 Slide Rule



For your consideration is a March 1974 6138-7000 “Slide Rule” Automatic Chronograph — An all original watch (dial, hands, case, and all mechanical components).

This 6138 is part of my personal collection of watches. I do not know the origin before my ownership. I just serviced this watch and it is running perfectly (more below).


The watch is completely original unto itself and I would rate the cosmetic condition as a 9.8/10. The case has not been polished and shows age and wear commensurate with a 47+ year old watch but is in amazing condition for the age. The dial is original to the watch and has a date stamp with the same month and year as the case date (34). The dial is the most amazing and flawless matte black. The dial and hands retain the very clean factory applied lume. The hands reset exactly to their vertical positions. Bracelet is an original Seiko oval link and is full length. The crystal is a NOS replacement.

Case Dimensions

Diameter: 45mm
Width (L-to-L): 45mm
Lug Size: 19mm
Height: 14.5mm


I serviced this 6138B movement 07/01/2021. That process includes a full cleaning and evaluation of all movement components and proper lubrication. Lubricants used were Moebius synthetic varieties appropriate for this watch movement type. The amplitude numbers are 230-240 range and the rate is +/- 2 sec/day. The case back, pushers and crown all have new, and factory correct seals.

This watch comes with a 100% money back promise of originality and a 1-year limited warranty on the movement from the time of sale. Shipping is to CONUS through USPS 2-day and flat fee for international shipping.