12 3/4”’ | Hand Wind | Sweeping Seconds | Date |

Remarks:

• Listed with 11 1/2”’ in the Flume catalog, but correctly with 12 3/4”’ at Boley online
• Movement family:
  • HPP 420: 12 3/4”’, automatic, HPP Supershock
  • HPP 421: 12 3/4, automatic, date, HPP Supershock
  • HPP 422: 11 1/2”’, hand winding, HPP Supershock
  • HPP 423: 11 1/2”’, hand winding, small date, HPP Supershock
  • HPP 4231: 12 3/4, hand winding, date, HPP Supershock
  • HPP 424: 10 1/2”’, hand winding, HPP Supershock
  • HPP 425: 10 1/2”’, hand winding, small date, HPP Supershock
  • HPP 431: 12 3/4”’, automatic, date, Incabloc
  • HPP 433: 10 1/2”’, hand winding, small date, Incabloc

• Listing ID: 4438
• Manufacturer / Brand: HPP
• Caliber: 4231
• Size in French Lignes: 12 3/4'''
• Size range mm largest diameter: 22 - 31 mm
• Shape: Round
• Winding: Manual (Crown)
• Hands Setting: Crown
• Seconds Hand: Sweeping seconds (central seconds)
• Escapement: Lever (Swiss, English, Glashütte)
• Date, Day, Month...: Date
• Jewels: 21
• Setting Lever Screw/Pin Position: Right
• Balance Position: Bottom (120 - 240°)
• Shock Protection: HPP Supershock
• Beats per hour: 18,000
• Balance Type: Nickel
• Power Reserve: Unknown
• Production Period: Unknown, probably around 1970
• Country: Germany
• Identification: Wheel train bridge marked with HPP 4231. Listed in the Flume K3 catalog from 1972.
• 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-11#post-2174349