Calibre 175 (and the similar calibre 177) is an ultra-thin hand-wound watch movement from Patek Philippe.

This ultra-thin movement is based on a 90 year old design from F. Piguet and remains in production today.

Patek Philippe used a F. Piguet ebauche to produce their own ultra-thin 9 ligne watch movement. Although based on this venerable design, Patek Philippe modified the movement extensively. They added their patented free-sprung Gyromax balance and finished the movement to Geneva Seal standards.

Cal. 175 beats at a leisurely 18,000 A/h, but the derivative Cal. 177 beats at a more modern 21,600 A/h. Apart from this, the movements are very similar.

Cal. 177 remains in production.

Cal. 175 and 177 was used in many watches, including the following popular references

• 175
  • Patek Philippe Calatrava 3520
  • Patek Philippe Golden Ellipse 3577
• 177
  • Patek Philippe Calatrava 3520
  • Patek Philippe 7180 (skeleton)

• Piguet 21, the ebauche