Seagull Caliber ST3600K Watch Movement

Manufacturer	Seagull
Caliber Number	3600K, ST3600K, ST36K, ST-3600K, ST36
Movement Type	Mechanical, manual-wind
Lignes	16.5”’
Diameter	36.60mm
Height	4.50mm thick
Jewels	17
Beats per hour	21,600 vph
Hand Size	2.0mm / 1.15mm / 0.27mm (needs confirmed)
Anti-Shock System	Incabloc
Hand-Windable?	Yes
Hacking Seconds?	No
Functions	Central hours, central minutes, small seconds at 9:00
Country of Manufacture	China
Known Models	Sea-Gull M222SK, Invicta 5001, Invicta 17265, Invicta 1090, Invicta 1088 (Add your watch to the comments below…)

The Seagull caliber 3600K is a mechanical hand-wound watch movement. There are no engravings or inscriptions on the movement, not even a jewel count.

It is said that this caliber ships from the factory without first being oiled or regulated. If you have a brand new, yet poorly performing timepiece with this movement, it’s possible that the watch brand did not service it during assembly.

Some of the topics covered in this caliber listing:

Gold/Silver Tone Versions:

The ST3600K is available in a steel (silver tone) finish and a gold tone finish. As far as we know, Seagull does not distinguish these options with different caliber numbers. This is odd, because without a way to distinguish between colors, then how do they perform the accounting and inventory management of the caliber? If anyone has even completed a purchase order for this caliber and recall a way to identify the color, please comment below.

What does the K stand for?

Tianjin Seagull is known for their mechanical manual-wind caliber ST3600 which is an ETA 6497 clone movement. The K at the end of 3600K is essentially the skeletonized version of that movement.

ST3600 VS ST36:

This movement is reportedly the same as the Tianjin caliber ST36. Tianjin and Seagull are the same company (Tianjin Seagull Watch Group), but they have offices in Tianjin, China as well as Hong Kong. Apparently the different caliber numbers correspond with where the movements ship out of.

Replacement Prices:

At the time of this post, replacement prices for the Seagull caliber ST3600K were found online in the range of $75.25 – 88.77 USD.

Video of the silver version:

Examples of watches with the ST3600K:

The ST3600K pictured below was found in this Invicta 5001.

More watches with the ST3600K:

Pros and Cons:

Pros: Based on a solid infrastructure that has been used for decades; Affordable compared to similar Swiss movements; Easy to work on.

Cons: Said to ship from the factory without oil or regulating, therefore if the watch brand doesn’t service the movement during assembly then the watch may have trouble in the future; Parts for Chinese watch movements are not well-organized and not easy to find, so you may need to get parts from another watch, or swap the movement entirely.

Additional Resources: