8 3/4”’ | Manual Wind | Pin Lever | No Second |

Remarks:

• PC = Protechoc shock protection
• Rocking bar winding
• Click on the dial side

• Listing ID: 251
• Manufacturer / Brand: Oris
• Caliber: 531 / 531 PC
• Size in French Lignes: 8 3/4'''
• Size range mm largest diameter: 0 - 22 mm
• Shape: Round
• Winding: Manual (Crown)
• Hands Setting: Crown
• Seconds Hand: None
• Escapement: Pin Lever
• Date, Day, Month...: None
• Jewels: Oris 531: 2 (both on the bridge side), Oris 531 PC: 0 ("capstones" made of plastic)
• Setting Lever Screw/Pin Position: Left
• Balance Position: Bottom (120 - 240°)
• Shock Protection: 531: Oris-specific, 531 PC: Kif Protechoc
• Beats per hour: 18,000
• Balance Type: Nickel
• Power Reserve: Unknown
• Production Period: Unknown, possibly around 1960?
• Country: Switzerland
• Identification: Barrel bridge marked with OWC and CAL. 531, 531 PC respectively. Manufacturer's data sheet available.
• Contributor ©: Uhrforum.de member Badener (Andreas Kelz)
• External Link: https://uhrforum.de/threads/identifizierte-uhrwerke-die-weder-bei-ranfft-lorenz-noch-im-watch-wiki-zu-finden-sind.86322/page-60#post-8509143