Miyota Caliber 6P23

The Miyota caliber 6P23 is a quartz movement with 0 jewels. This movement is assembled in Japan and is considered to be a replaceable movement.

As part of the 6P family of multi-function quartz movements, the notable features of the 6P23 are the vertical 12-6 subdials to display the date and 24 hour time (military time).

Accuracy:

Miyota states the accuracy of this movement to be +/-20 seconds/month.

Changing the Battery:

When looking for a replacement battery, you will want to find a cell number SR621SW / 364 (silver oxide). The battery should last up to 3 years.

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There is a very small retainer spring that holds the battery in place. In the picture below, it can be seen above the number “280-34”. When removing the battery, carefully move this part back in the space provided. When inserting a new cell, wedge the battery downward into that retainer spring so that the battery in under it, then push in against it and downwards to secure the battery in place.

Below is a close-up of the holder/tab. As you can see, it is very small and easy to break or bend so handle with care.

You can pull the crown out to time-setting mode to hack the movement (stop the seconds) and conserve energy when not wearing your watch for longer periods of time. Once the battery is depleted, be sure to remove it from the watch even if you don’t plan on wearing it, so that the cell does not leak into the movement.

Crown/Stem Removal:

If you need to get the movement out of the watch case, then you will need to remove the stem/crown first.

Look for the small arrow to the right of the “No Jewels” text. The crown must be in neutral position (against the case). The detent button is in the hole where the arrow is pointing.

If the crown is in time-setting mode, the button will hide (see image below). It’s supposed to be a foolproof design.

Replacement Price:

At the time of this post, prices for the caliber 6P23 quartz movement were found online between $14.99 and $22.95 USD.

Wholesale:

To order the caliber 6P23 from Miyota, the minimum is 1,000 pieces. The production lead time is said to be about 2 months.

Related Calibers:

There are a few calibers in the same 6PXX family with non-chronograph subdial layouts:

• 6P23 – 12-6 subdials, date, 24 hour indicator
• 6P25 – 3-9 subdials, day/date
• 6P27 – 6-9-12 subdials, day/date, 24 hour indicator
• 6P29 – 3-6-9 subdials, day/date, 24 hour indicator

Note: the caliber 6P79 is a high-hand version to accommodate thicker dials.

Examples of watches with this caliber:

This movement was found in a Philip Stein Sport watch. The caseback has a piece of copper metal inside.

Additional Resources:

• Official instruction manual (pdf)
• Official technical drawings