ISA Caliber 336/168

ISA caliber 336 is 5 jewel quartz movement that is made in China. This caliber is part of the ISA Slender family of quartz movements. It is considered to be a repairable movement by ISA, but finding parts may be challenging.

The most up to date tech sheets on this caliber appear to be from 07/01/06. ISA is no longer producing movements and this caliber has been discontinued. At the time, ISA had offices in Switzerland, France, and Hong Kong.

Caliber Number:

Watches with this caliber are usually marked ISA Cal. 336, but the full caliber number of this particular version is 336/168. The second set of numbers after the dash depend on the hand configuration. This movement is also signed 32577-7 with the letter K nearby (if you have insight as to what this number is, please comment below).

Similar Calibers:

There are similar caliber numbers based on the 336 family of ISA movements.

• 336/101 – Central seconds
• 336/130 – Hours and minutes only, no seconds
• 336/168 – Small seconds at 6:00

Expected Battery Life:

ISA claims that a new battery in the 336/168 movement will last for about 44 month.

This movement has a hacking mechanism (to stop the seconds hand), which ISA also refers to as a current breaker. Hacking the movement by pulling the crown out to time setting position will reduce battery drain when you’re not use your watch for a long period of time. Keep in mind that the battery can still leak and damage the movement, so it is a good idea to change the battery even if you don’t wear the watch often.

When changing the battery, you should see a green insulator film (see below) under the battery cell. Make sure this film is in place when you install the new battery. Its purpose is to prevent the battery from shorting.

Battery Number:

The battery you need for this watch is cell number SR626Sw aka 377/376. This is a small watch battery at 6.8mm in diameter, 2.6mm thick. 1.55V, 28mAh.

Low Battery Indicator:

When the battery is low on the ISA caliber 336 the second hand will skip a few seconds.

Accuracy Rating:

According to ISA, the claimed accuracy of the 336/168 is between -6 to +9 seconds per month. That breaks down to about -0.2 – +0.3 seconds per day. This is within normal operating temperatures of 0-50 degrees C.

Replacement Price

At the time of this post, replacements for the ISA caliber 336/168 were found online in the range of $23.40 to 24.95 USD.

Examples of watches with this movement:

This example of ISA caliber 336/168 was found in a 53mm Invicta Russian Diver model 7275. The movement has a small seconds hand at 6:00, but for this model Invicta turned the movement around so the crown is at 9:00 (lefty) and the seconds are at 12:00. It’s also interesting to see that the movement is engraved with INVICTA, which appears to have been done by ISA since it is in the same depth and style as the other markings. Near the Invicta label, it is also signed with “AT 1”, which could be a date code or related to a purchase order.

Additional Resources:

• More ISA calibers here