Reference:Movements: Difference between revisions

Several UK auction catalogues treat the three- and four-digit numbers found on movements in refs 1862, 1490, and 1855 as calibers. The documented numbers are 510, 579, 841, 1004, 1130, and 1439, with weaker evidence for 701 and a single record of 1759. They are almost certainly movement serials read from the plate. Continental catalogues identify the same movement class by grade and the T.S. size code instead. Cal. 414 and Cal. 527 have no documented connection to the Rolex Prince. The number 971A is a Prince case reference, not an established caliber designation; Antiquorum catalogued that reference in 1989 with a T.S./300-family movement. Fabsuisse labels the movement in its separate ref. 3937 dealer listing “Cal. 971A,” but the auction records reviewed here do not confirm that designation. Treat it as an unverified dealer attribution unless a readable movement marking supports it.

| Prince Brancard ref. 1855, serial 143**, circa 1930

| 8-position adjustment, against the more typical 6

| [[Reference:6718|6718]]; exact-reference catalogues list Cal. 2030 in individual watches

| 17 in Aste Bolaffi lot 34; 19 in Antiquorum lots 229 and 233

The Field Manual lists Cal. 520 for ref. 1858; Aste Bolaffi identifies movement 1143 as Hunter 8¾ (520), and Vintage & Prestige and WatchNet list Cal. 520 for their ref. 1858 examples. Hodinkee's 2024 family guide instead assigns Cal. 620 to the first series beginning with ref. 1858. Phillips and Antiquorum's 2006 and 2013 lots list 8¾-line movements; Antiquorum's 2021 Hong Kong entry gives 9¾ line without naming a caliber. The lots report 17 jewels for Bolaffi movement 1143 and 19 for the two Antiquorum movements.

Cal. 635 belongs to the early automatic family related to Cal. 620. General movement references describe a subsidiary-seconds layout, 17 jewels and a larger movement than the 9¾-ligne measurements in two 3130 auction entries. Antiquorum catalogued 3130 cases 54932 and 474617 with Cal. 635, 19 jewels, 9¾ lignes and subsidiary seconds ([lot 256](https://catalog.antiquorum.swiss/en/lots/rolex-lot-108-256); [lot 169](https://catalog.antiquorum.swiss/en/lots/rolex-lot-108-169)). Christie's identified case 443093 as Cal. 635 with 19 jewels but centre seconds ([2007 lot 2858](https://www.christies.com/en/lot/lot-5008631)). The latter catalogue description conflicts with the usual seconds layout. Without a visible caliber stamp, keep the centre-seconds attribution attached to that lot; do not treat it as a confirmed Cal. 635 variant.

A260 powered the first Submariner references, 6204 and 6205, from 1953 to 1955. "A.260" is Rolex's size-family code for this movement class, comparable to the Prince family's "T.S." code. Its non-butterfly rotor distinguishes it from the butterfly-rotor Cal. 1030. Hodinkee traces A260 to a movement used in earlier Oyster Perpetuals and later Bubblebacks, predating its Submariner fitment. The registry uses 17 jewels; some auction descriptions give 19, so the count should be checked against the individual movement.

Produced from 1959 to 1965, Cal. 1565 is the early ref. 1675's "caller" GMT movement: its 24-hour hand remains linked to the main hour hand rather than independently adjustable. Rolex kept that layout until Cal. 3085. The 1565 introduced a free-sprung Breguet overcoil with Microstella regulation to this lineage, replacing the index used by earlier sport calibers. Rolex's [https://www.emmywatch.com/wp-content/plugins/watchsearch/inc/documents/rolex--1565--movement_parts.pdf Cal. 1565 parts sheet] describes an automatic calendar movement, shows "1560" engraved on its self-winding bridge, and lists part 7956, the date-indicator seating, for refs. 1500, 1501 and 1503. The [https://www.clubderelojeria.com/comunicaciones/R/ROLEX/rolex1575/ROLEX%201575.pdf Cal. 1575 parts catalogue] lists date-indicator parts for those same case references. The Vintage Rolex Field Manual also lists [[Reference:1500|ref. 1500]] in its Cal. 1565 Date table ([https://irp-cdn.multiscreensite.com/0b5fdf83/files/uploaded/1.0%20RolexBook-23Mar.pdf The Vintage Rolex Field Manual, caliber table]). These factory lists document service-parts applications; movement-level inspection determines the caliber fitted to a particular watch. Auction catalogues call ref. 1501 Cal. 1560 or 1570, matching the bridge numbers shown in the 1565 and 1575 parts sheets. The records leave watch-specific fitment and changeover years unresolved. See [[Reference:1500|ref. 1500]], [[Reference:1501|ref. 1501]] and [[Reference:1503|ref. 1503]].

Cal. 1570 is the 19,800-vph revision of the 1560, introduced in 1965. Christie’s identifies Cal. 1570 in ref. 1011 case 692498, dated circa 1962; its lot chronology overlaps the ref. 1011 Cal. 1560 examples and does not establish a changeover. See [[Reference:1011|ref. 1011]]. Monaco Legend lists Cal. 1570 in a 1966 pink-gold 1013, Gazette Drouot in a circa-1968 example and Rago in a 1978 example. The 1013 records document both calibers but leave their changeover unresolved. See [[Reference:1013|ref. 1013]]. One Artcurial ref. 1005 lot is catalogued with Cal. 1550, despite a chronometer-dial description; other 1005 catalogues list 1560 or 1570. This single lot does not establish a 1005 movement variant or resolve whether the movement is original. It retains the free-sprung Breguet overcoil and Microstella regulation, with adjustment to temperature and five positions. Family-wide bridge engraving causes date movements such as the 1575 in a ref. 1665 to appear marked 1570; the engraving alone does not identify the exact caliber. Phillips identifies Cal. 1570 in a circa-1985 ref. 1024, while Dorotheum lists it on a circa-1965/70 example; those ref. 1024 dates overlap its Cal. 1560 records. Christie’s, Antiquorum, Phillips, Dorotheum and Bonhams also catalogue Cal. 1570 in ref. 1501 examples; see [[Reference:1501|ref. 1501]]. These lot labels do not establish a 1501 changeover year.

The 1575 shares factory balance assembly 8106 with the 1570 and related family members. It has shock protection on the escape wheel on both dial and movement sides, as well as on the balance. The Vintage Rolex Field Manual lists [[Reference:1500|ref. 1500]] as a Date fitment in its Cal. 1575 table ([https://irp-cdn.multiscreensite.com/0b5fdf83/files/uploaded/1.0%20RolexBook-23Mar.pdf The Vintage Rolex Field Manual, caliber table]); a [https://www.clubderelojeria.com/comunicaciones/R/ROLEX/rolex1575/ROLEX%201575.pdf Rolex Cal. 1575 parts catalogue] lists date-indicator parts for refs. 1500, 1501 and 1503. Auction catalogues more often describe 1500 examples as Cal. 1570. [https://www.bobswatches.com/rolex-blog/watch-review/vintage-week-rolex-oyster-perpetual-chronometer-date-ref-1500.html Bob’s Watches] explains the 1570 bridge engraving on date-equipped 1575-family movements; the engraving alone does not establish the caliber beneath it. The available records do not identify a watch-specific changeover. Other documented fitments include the Submariner 1680, GMT-Master 1675 from about the 1.4-million serial range, Explorer II 1655 and Sea-Dweller 1665.

* [https://www.watchnet.co.jp/en/item/view/5300 WatchNet Japan, product A-6378 — seller-attributed Cal. 520]