Review Seagull ST5

In 1966 calibre ST5 was developed by Tianjin wath factory (天津手表厂) this factory is now known as the Tianjin Sea-gull watch factory (天津海鸥手表集团公司). The calibre ST5 is the first truly Chinese developed and manufactured watch movement. Several variant have been made including an automatic version (I have yet to work review the autowinder) 

Calibre 5TS variants:

  • ST5-A: No calendar
  • ST5-B: Date variant
  • ST5-K: 21,600 bph escapement upgrade.ST5-D: Automatic winding (1971) (Not reviewed yet)

Tianjin watch factory calibre ST5

  • Made approximately: 1966-19XX
  • Made in China
  • Power reserve around: 40h
  • 19-23 Jewels 
  • 18000-19800 B/A
  • Lift angle 52°
  • DM 
  • H 

Surface finish of the earlier variations are of a basic nature, while the later variant have a rather unique deep cut curving starburst pattern known as Sea-full stripes. 

Top surface finish on plates: 5-7* Points

Surface finish on screws: 6Points

Surface finish on ratchet and ratchet wheel: 6 Points

Movement Jeweling: 8 Points

Base movement if fairly modern for 1966.

Movement design innovation (for 1966):  7 points

The ST5 base plate has no decoration and a overall rough utilitarian finish. Winding, date and setting mechanisms have a basic finish. Gear train is well made. Setting the time feels balanced and smooth. Date mechanism is well made and has a snappy date change. 

Base plate finish:4 Points

Setting and winding mechanism: 5 Points

Date change snappiness: 8 Points

Gear-train finish: 6 Points

Movement durability: 8 Points

All versions have an adjustable stud carrier.

3 Bonus points

ST5-K variants beat error upgrade: 

3* Extra innovation points for higher beat rate.  

These Tianjin moments in good condition keep excellent time keepers.  

Accuracy: 8 points 

Power reserve of 40 hours is sufficient

Power reserve: 7 Points

Tiajin ST5 points summary: 

Surface finish on bridges and top side of base plate: 5-7*

Surface finish screws: 6

Surface finish on ratchet and ratchet wheel: 6

Movement Jeweling: 8

Movement innovative design for ca 1966: 7 

Base plate finish: 4

Setting and winding mechanism: 5

Date change snappiness: 8*

Gear-train finish: 6

Movement durability: 8

Total bonus points: 2-5*

Autowinder: Yet to be reviewed. 

Accuracy: 8

Power reserve: 7

Grand total: 72-82*