The History of the Calibers | Schwanke-Kasten Jewelers

Breitling B01 in-house caliber | Schwanke-Kasten Jewelers

For the most passionate of watch enthusiasts, the word “caliber” or “calibre” as the Swiss and French refer to them, carries a vast importance. They can generally tell a story of a brands innovation and maturation based on the caliber.

When we say caliber, we are referring to the movement or powerhouse of a mechanical watch. Although originally the caliber referred to the physical size of the movement. Many watchmakers now use the caliber number as a form of identification. Hence, a timeline is formed as watchmakers produce new movements or refine current ones.

Now when the general population hears the word, “caliber”, they think of the diameter of a bullet casing. However, in a fairly recent Hodinkee article, the first usage of a caliber to describe a watch movement occurred around 1715 when it referenced the watch size. The article then goes on to explain how various watchmakers began using caliber referencing various sizes and complications of their watches movements.

Take Breitling’s in-house movements for example. Back in 2012, Breitling produced their first in-house (100% designed, created and assembled by Breitling) movement, the B01.
  • The B01, which is a 70-hour power-reserve, chronograph with a date wheel complication, became the base mold for their in-house movements. 
  • The B02 is a manual-wound, 24-hour dial chronograph found in the Cosmonaut. 
  • The B03 is their latest in-house, the split seconds Navitimer Rattrapante. 
  • B04 is essentially the B01 with an additional complication of a GMT hand, 
  • B05 takes it further and delivers a world-time function (or Unitime as Breitling refers to it). 
  • B06 is a 30-second tachymeter. 
  • The B12, featured in the Avenger Hurricane is a combination of the B01 automatic movement and the 24-hour dial of the B02.
  • The B20 is a combination of the B01 and Tudor’s MT5612 

As you can see, complications and modifications on an existing movement can often be traced back to a brand’s movements. Stop by Schwanke-Kasten Jewelers to see our exceptional collection of fine Swiss timepieces.