Rolex 520

Last updated: July 26, 2025
A clock with gears inside and a magnifying glass revealing a gear, symbolizing time management and analysis, enhanced by a Caliber Index to represent precision and organization.

Brand

Caliber Number

520

Production Period

1930s – 1940s

Lignes

5.9 x 10.9”’

Diameter

N/A (Form Movement, 13.3mm x 24.6mm)

Height

3.45 mm

Power Reserve

Unconfirmed

Frequency

18,000 bph (2.5 Hz)

Jewels

15

Escapement

Swiss Lever Escapement

Anti-Shock Device

None (typical for the era)

Hand Count

2 (Hours, Minutes)

Manufacture Region

Unconfirmed

Functions

Manual Winding, Hours, Minutes

Rolex 520 Description

The Rolex Caliber 520 is a manually wound, rectangular “form” movement from the Art Deco era of the 1930s and 1940s. It was designed specifically for ladies’ “Tonneau” (barrel-shaped) and rectangular watches. True to the elegant style of the period, the Caliber 520 is a simple time-only movement, featuring only hour and minute hands, which allowed for clean, uncluttered dial designs. It represents a key part of Rolex’s history in creating high-quality, fashionable ladies’ timepieces.

Watches Using The Rolex 520 Caliber

Vintage Rolex Oyster Perpetual wristwatch with a gold case, cream dial, and black textured leather strap.
A silver and rose gold Rolex Oyster Perpetual wristwatch, model 3353, with a white face and a sleek metal bracelet.