Seiko Caliber 7T62
|Caliber Number||7T62 / 7T62A|
|Diameter||12”’ (24.1mm x 27.6mm)|
|Battery Cell Number||395/399 (SR927W)|
|Quartz Type||Tuning fork type quartz crystal|
||32,768 Hz (cycles per second)|
||4 part step motor|
|Stem||351580 (tap 10 )|
|Hand Sizes||1.10mm / 0.65mm / 0.20mm for chrono and subdials|
|Functions||Hours, minutes, small seconds, central chronograph seconds, split time, 60 minute counter, date, alarm|
|Country of Manufacture||Japan|
|Known Models||Seiko Velatura (add more in the comments below)|
This Seiko caliber 7T62 (actually marked 7T62A) was found in a Velatura model watch here. This quartz movement was made in Japan and features an alarm and chronograph. It is a 0 jewels movement. The caseback has a Piezo attached for the alarm tone (part 4589 801).
7T62 vs YM62
You may also see a similar caliber known as the Hattori or SII YM62. The YM62 is basically the same movement as the 7T62 except that it is sold to other watch companies and used in non-Seiko branded timepieces. Learn more about Hattori/SII/TMI/Epson here. It may be possible to interchange these movements, but the height is slightly taller than the 7T62 (see here).
7T62 vs 7T92
The caliber 7T92 is another popular Seiko quartz chronograph movement. These two calibers are sometimes mixed up. The big difference is that the 7T62 listed here has an alarm and a 1/5 second chronograph that measures up to 60 minutes. The 7T92 has a 1/20 second chronograph that measures up to 12 hours. The 7T92 does not have an alarm.
7T62 vs 7T32
You may see other collectors refer to the caliber 7T62 as an evolution of the original 7T32 quartz movement, however, keep in mind that one huge difference between the two movements is that after replacing the battery, the 7T32 required performing an AC (or all clear) reset by using a wire, tweezers, or a paperclip to touch the positive side of the installed battery with the AC contact (there will be a hole labeled “AC” with an arrow). The caliber 7T62 does not have an AC button or hole.
The chrono hand on the 7T62 pulsates 5 times per second. This also allows this movement to measure 1/5 of a second when using the chronograph feature. To reset the central chronograph hand: pull the crown to position 2 and hold the bottom chrono pusher until the hand is at 12:00. Long pressing will make the hand advance faster.
Alarm / Second Time Zone
The 7T62 has an alarm function that doubles as a second time zone subdial. The alarm can be set to ring once in the next 12 hours. To set the alarm, pull the crown to position 1 then press the bottom pusher to advance the alarm time. when you get the time you want, push the crown back in.
Seiko claims that the caliber 7T62 will maintain accuracy of +/- 15 seconds per month at normal operating temperatures of about 41F to 95F. The alarm is accurate to +/- 1 minute.
Replacement prices of this watch movement were found online in the range of $65.95 – $71.99.
In the manual, Seiko claims that the battery should last approximately 3 years. Keep in mind that the battery will drain faster if you leave the chronograph second hand running – specifically if the chrono is used for more than 2 hours per day or if the alarm rings more than 20 seconds per day. There is also a low battery indicator which will cause the small second hand to jump every 2 seconds. Low battery mode also prohibits the alarm from sounding off. The time on your watch will maintain accuracy even in low battery mode.
The original battery in the watch was also made in Japan by Seiko. The size is SR927W which should convert to a 395 or 399 cell.
Resetting the Chronograph Hand to Zero
There are two hands related to the chronograph function: The central 1/5 second hand and the stopwatch minute hand subdial. To reset the chronograph hands to 12:00 or zero on the dial, first pull the crown out to position 2 (2 clicks to time-setting mode). Hold the top chronograph button for about 2 seconds until the stopwatch minute hand turns in a full circle. Now use the bottom chrono button to advance the hand where you want it (holding the button will make the hand advance faster). Press the top chrono button again to switch to adjusting the big central seconds hand. Press the bottom chrono button to advance the hand to where you want it. Push the crown back in.
More watches with this movement:
Please share your experience with the caliber 7T62 in the comments below…