Cal. 6810 is an ultra-thin watch movement from Seiko produced between 1973 and 1998. It was derived from the original 1969 Cal. 68A and features an unusual shape, with flat sides, for use in rectangular watches. Despite this, most watches using Cal. 6810 feature round dials and cases that could accommodate a round movement.
Cal. 6810 was produced throughout the 1970s and used in a series of ultra-thin dress watches marketed under the “U.T.D.” name. These were no longer in the Seiko catalog after 1978, and the movement was retired.
In 1991, Seiko creates a special reissue of the original U.T.D. watch to celebrate the company’s 110th anniversary. This coincided with renewed interest in mechanical movements and Seiko brought the movement back into production in 1993. The resulting SCVL series was Seiko branded but priced quite expensive relative to other models. At that same time, Seiko created an upscale version of the movement, Cal. 6870, finished and regulated for use in the emerging Credor brand. By the end of the decade, Seiko had retired Cal. 6810 once again, assigning the Cal. 68 family entirely to the Credor brand.
