Seiko Caliber Y675

The Seiko caliber Y675 is essentially the SII (Seiko Instruments Inc.) version of the widely known Seiko caliber 7S25 (no hacking, no manual-winding). There is not a lot of information available for the Y675, this is partly due to it being an older caliber which has now been discontinued. For more information on its counterpart, read the Seiko 7S26 caliber listing.

Y675 VS 7S25:

The cal. Y675 was made for watches outside of the main Seiko brand, such as Alba, Pulsar, Lorus, and J. Springs (aka Japan Springs) – all Seiko owned companies. If you have a watch with this movement, please share it in the comments below.

Similar to the 7S25, there are lettered evolution variants of the Y675: Y675A, Y675B, and at least up to Y675C. It is not confirmed if the changes made in the 7S25 A/B/C correspond directly to the A/B/C in the Y675, but it’s likely safe to assume as much until the community finds evidence to the contrary.

Interesting note: The official instruction manual from Seiko combines information for calibers 7S25, 7S26, Y675, and Y676.

Country of Origin:

Many seller list watches with this movement as “Japan”. Although Seiko is based in Japan, it doesn’t mean their products are all made in Japan. Sometimes the Y675 is signed Japan (such as in some Seiko Onitsuka Tiger models) and sometimes there is no country of origin – similar to what SII/TMI is doing with the NH35A now. It’s unlikely that Seiko makes movements in Japan and not mark them as such. If you have a Y675 signed “Japan”, please add it below.

For what it’s worth, it does seem like newer versions of the Y675C tend to be signed with Japan on the rotor.

Y676 VS Y675:

There is a similar caliber Y676 with the main difference being that the Y675 is a date only and the Y676 is a day-date.

Additional Resources:

• Official instruction manual (pdf)
• List of Seiko movements