Reference:2940: Difference between revisions

| Cal. 9¾’’’, 17 jewels (some 18j); some examples Cal. 630

The 2940 is the volume wartime Bubbleback. The 3131 and its sweep-seconds twin 3132 had proven in 1936 that the two-piece Oyster could be manufactured at scale; the 2940 is the reference that made the same case architecture available in steel and inexpensive gold cap. It carries the sweep-seconds configuration that the 3132 pioneered, a center-mounted seconds hand running off Cal. 9¾’’’ rather than a subsidiary register at 6, and pairs it with a case sized for a masculine wartime wrist. Production runs from roughly 1940 through 1949, with the concentrated peak falling in the five years from 1942 through 1947.

When a 2940 appears for sale with hooded lugs, the presumption is modification. The burden is on the seller to demonstrate otherwise, and the published collector record does not contain a documented example where that demonstration has succeeded.

The 2940’s movement is non-hacking. Pulling the crown to the setting position stops the hands from advancing but the seconds continue to sweep; setting to the exact second requires a fractional backlash adjustment that is second nature on contemporary vintage Rolex but foreign to any Rolex made after the introduction of hacking seconds in the 1970s.

Cal. 630 is cited on some 2940 examples and is the formal numbered caliber for the 9¾’’’ sweep-seconds configuration. The two designations refer to the same movement family under different naming conventions. The ligne measurement (9¾’’‘) is older, and the numbered caliber (630) is the catalog reference Rolex used in service documentation. A 2940 described with Cal. 9¾’’’ and a 2940 described with Cal. 630 are, in practice, the same watch.

The 2940 carries the widest dial catalog of any Bubbleback reference. Some of this breadth reflects Rolex’s pre-war practice of configuring dials to retailer specification; some of it reflects the reference’s long production run across multiple export markets; some of it reflects refinishing activity over the subsequent eight decades.

Salmon-finish dials are scarcer still. The Heritage Auctions “Two Tone Salmon Dial” example, a c.1942 2940, is the best-documented salmon dial in the public auction record, and any appearance at auction or dealer inventory draws collector attention disproportionate to the reference's general market position.

Dealer-signed dials surface on 2940s more frequently than on most later Rolex references, reflecting the 1940s practice of retailers commissioning co-signed dials for their own stock. The “Erbe Basel” signature, for the Erbe jewelry retailer in Basel, Switzerland, is one of the documented dealer signatures on 2940 dials.

Stainless steel is the most commonly encountered. The 2940 was Rolex’s workhorse steel Bubbleback of the wartime period, and steel examples constitute the bulk of the surviving population. The Phillips 2015 Lot 277 example is steel; so are the majority of dealer inventory listings across 1stDibs, Chrono24, and specialist vintage dealers.

The 2940 carries one clear retailer-specific branch: the Zell Bros “Turtle Perpetual Timer.” It is still a standard 2940 underneath, but the name and dial signature are enough to put it in its own small collector lane.

The Turtle example is one of several mid-century US retailer variants where a jewelry chain contracted with Rolex for signed-dial stock and gave the resulting watches retail-specific names. The practice was more common on 1940s and 1950s Rolex production than it is on any modern reference; the Zell Bros Turtle is the 2940’s best-known example.

The 2940 is a reference where dial configuration drives value more decisively than case material or condition alone. A standard Arabic-radium steel 2940 in good unrestored condition trades in the low-to-mid four figures. A California-dial steel 2940, in comparable condition, trades at roughly double that. A salmon or sector dial example can push to the top of the reference’s documented range. A 24-hour military 2940 surfaces rarely enough that price discovery happens case by case. The dial catalog is the first item of diligence on any 2940 purchase.

The 2940 trades primarily through specialist dealer inventory and the secondary auction market rather than at major Geneva houses. Phillips and Heritage have handled examples; Sotheby’s and Christie’s have occasionally included 2940s in mid-tier vintage lots; Antiquorum and Bonhams have listed them in catalog sales. The bulk of market activity happens through vintage Rolex specialist dealers, forum-adjacent private sales, and platforms like Chrono24 and 1stDibs. Price discovery is accordingly uneven, and a given configuration can trade at widely varying prices depending on venue and market conditions.