Certina Calibre 320

Certina started manufacturing calibre 320 in the late 1930’s. The basic model is not shock protected, but most later variants had inca shock as standard. Calibre 321 is close to identical but has another bridge design.

Certina/Kurth Freres calibre 320/321

  • Made approximately ca: 1939-1955
  • Made in Switzerland
  • Power reserve 42h
  • 15 Jewels 
  • 18000 B/A
  • DM 27.0mm 
  • H 3.8mm

Surface finish on calibre 320 has Rhodium plating with gilt infilled lettering. Gear train bridge has fine design with beveled edges and a fine finishing.  Screws are polished to a high standard. Crown and ratchet wheel has fine finish

Surface finish on top side of the plate and bridges: 7 Points

Surface finish on screws: 8 Points

Surface finish on crown and ratchet wheel: 7

Movement Jeweling: 6 points 

Movement design innovation (for ca 1939):  6 points

The Certina base plate on the calibre 320 is quite fine with various designs, this one has a spiral starburst finish and a polished surface. Winding/setting mechanism is well made with polished screws.

Base plate finish: 8 Points

Setting and winding mechanism: 7 Points

Gear-train finish: 8 Points

Movement durability: 6 Points

The very first models are not shock protected, but most later models are fitted with inca shock. 

Shock protection: 3*

Calibre 320 utilises a flat hairspring and accurate when in good condition.

Accuracy: 8 points 

Power reserve of 42 hours is good.

Power reserve: 7 Points

Certina/Kurth Freres calibre 320/321 points summary: 

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

Surface finish top screws: 8

Surface finish on ratchet and ratchet wheel: 7

Movement Jeweling: 6

Movement innovative design for ca 1937: 6 

Total bonus points: 3

Base plate finish: 7

Setting and winding mechanism: 8 

Gear-train finish: 8

Movement durability: 6

Accuracy: 8

Power reserve: 7

Grand total: 78-81*