Reference:pre-daytona-chronographs: Difference between revisions

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{{#seo:

|title=Rolex Pre-Daytona Chronographs — ~~1935–1968~~ Guide | Rolexopedia

|title=Rolex Pre-Daytona Chronographs — 1920s–1968 Guide | Rolexopedia

|description=Rolex chronographs ~~before~~ the ~~Cosmograph Daytona:~~ Antimagnetique~~, Monoblocco, tonneau Oyster~~ and ~~round-~~Oyster ~~references leading~~ to the 6238 and overlapping 6239.

|description=Rolex hand-wound chronographs from the early hinged ref. 2021 monopusher through Antimagnetique and Oyster models to the 6238 and overlapping 6239.

|keywords=Rolex chronograph, Pre-Daytona, Antimagnetique, Monoblocco, Barilotto, 2508, 3525, 3668, 3833, 4099, 4500, 4537, 4767, 5034, 6034, 6234, 6238, Valjoux 23, Valjoux 72, vintage Rolex

|keywords=Rolex chronograph, Pre-Daytona, 2021, Antimagnetique, Monoblocco, Barilotto, 2508, 3525, 3668, 3833, 4099, 4500, 4537, 4767, 5034, 6034, 6234, 6238, Valjoux 23, Valjoux 72, vintage Rolex

|image=Pre-daytona chronographs vintage poster.webp

|image_alt=Rolex pre-Daytona chronograph reference photograph

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|og_type=article

|published_time=2026-04-30T03:24:59Z

|modified_time=2026-09-~~28T00~~:00:~~00Z~~

|modified_time=2026-10-06T08:27:07Z

|robots=index,follow,max-image-preview:large

}}

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</div>

~~Rolex’s chronograph references before~~ the ~~Cosmograph 6239 use several~~ case ~~families~~ and ~~Valjoux-derived manual movements. The~~ 3525 ~~introduced a two-pusher chronograph in a Monoblocco Oyster case;~~ later tonneau and round Oyster ~~references followed~~. The 6238 ~~is commonly called~~ the ~~Pre-Daytona because its 36mm round~~ case, pump pushers, dial tachymeter and Valjoux 72 family ~~sit close to the 6239~~. ~~The name is a collector term, and~~ the production ~~dates overlap~~.

This guide follows Rolex hand-wound wrist chronographs from the early hinged-case 2021 monopusher, through the non-Oyster 2508 and Oyster 3525, to later tonneau and round Oyster models. The 6238 sits near the Cosmograph 6239 in case size, pump pushers, dial tachymeter and Valjoux 72 movement family. Collectors call it the Pre-Daytona; its production overlaps the 6239.

== Early single-button chronographs (1920s–1930s) ==

The 2021 is a large, hinged-case monopusher documented in gold and steel. Auction catalogues date individual examples from the 1920s into the 1930s, and disagree on movement size and the date of the same case. [[Reference:2021|See the reference file for the examples and source records.]]

{| class="wikitable" style="width:100%;"

|-

! Reference !! Dated examples !! Case !! Movement !! Key distinction

|-

| [[Reference:2021|2021]] || 1920s–1930s catalogue estimates; start and end unconfirmed || 39–41mm, round hinged case; gold and steel examples || Manual chronograph; published dimensions and attribution vary || One side-mounted button; white-enamel, silvered and black dials documented

|}

== Antimagnetique era (mid-1930s to late 1940s) ==

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! Era !! Movement !! Case construction !! Pushers !! References

|-

| ~~Pre~~-Oyster (1930s–40s) || Published descriptions conflict: 13-ligne or 14-ligne; Valjoux 22, V23 or VZ || Round snap-back, non-Oyster~~; no inner-case specification established here~~ || Two; oval/olive or rectangular || [[Reference:2508|2508]]

| Early monopusher (1920s–30s) || Case-specific descriptions vary; no shared caliber assigned || Round, hinged, non-Oyster; 39–41mm examples || One side button || [[Reference:2021|2021]]

|-

| Non-Oyster two-pusher (1930s–40s) || Published descriptions conflict: 13-ligne or 14-ligne; Valjoux 22, V23 or VZ || Round snap-back, non-Oyster || Two; oval/olive or rectangular || [[Reference:2508|2508]]

|-

| Monoblocco Oyster (1939–1946) || Rolex Cal. 13 (Valjoux 23 VZ) || One-piece upper case, screw-down caseback || Pump || 3525, 3668, 3833

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 {{DISPLAYTITLE:Rolex pre-Daytona chronographs}}
 {{#seo:
-|title=Rolex Pre-Daytona Chronographs — 1935–1968 Guide &#124; Rolexopedia
+|title=Rolex Pre-Daytona Chronographs — 1920s–1968 Guide &#124; Rolexopedia
-|description=Rolex chronographs before the Cosmograph Daytona: Antimagnetique, Monoblocco, tonneau Oyster and round-Oyster references leading to the 6238 and overlapping 6239.
+|description=Rolex hand-wound chronographs from the early hinged ref. 2021 monopusher through Antimagnetique and Oyster models to the 6238 and overlapping 6239.
-|keywords=Rolex chronograph, Pre-Daytona, Antimagnetique, Monoblocco, Barilotto, 2508, 3525, 3668, 3833, 4099, 4500, 4537, 4767, 5034, 6034, 6234, 6238, Valjoux 23, Valjoux 72, vintage Rolex
+|keywords=Rolex chronograph, Pre-Daytona, 2021, Antimagnetique, Monoblocco, Barilotto, 2508, 3525, 3668, 3833, 4099, 4500, 4537, 4767, 5034, 6034, 6234, 6238, Valjoux 23, Valjoux 72, vintage Rolex
 |image=Pre-daytona chronographs vintage poster.webp
 |image_alt=Rolex pre-Daytona chronograph reference photograph
@@ Line 9: / Line 9: @@
 |og_type=article
 |published_time=2026-04-30T03:24:59Z
-|modified_time=2026-09-28T00:00:00Z
+|modified_time=2026-10-06T08:27:07Z
 |robots=index,follow,max-image-preview:large
 }}
@@ Line 19: / Line 19: @@
 </div>
-Rolex’s chronograph references before the Cosmograph 6239 use several case families and Valjoux-derived manual movements. The 3525 introduced a two-pusher chronograph in a Monoblocco Oyster case; later tonneau and round Oyster references followed. The 6238 is commonly called the Pre-Daytona because its 36mm round case, pump pushers, dial tachymeter and Valjoux 72 family sit close to the 6239. The name is a collector term, and the production dates overlap.
+This guide follows Rolex hand-wound wrist chronographs from the early hinged-case 2021 monopusher, through the non-Oyster 2508 and Oyster 3525, to later tonneau and round Oyster models. The 6238 sits near the Cosmograph 6239 in case size, pump pushers, dial tachymeter and Valjoux 72 movement family. Collectors call it the Pre-Daytona; its production overlaps the 6239.
+== Early single-button chronographs (1920s–1930s) ==
+The 2021 is a large, hinged-case monopusher documented in gold and steel. Auction catalogues date individual examples from the 1920s into the 1930s, and disagree on movement size and the date of the same case. [[Reference:2021|See the reference file for the examples and source records.]]
+{| class="wikitable" style="width:100%;"
+|-
+! Reference !! Dated examples !! Case !! Movement !! Key distinction
+|-
+| [[Reference:2021|2021]] || 1920s–1930s catalogue estimates; start and end unconfirmed || 39–41mm, round hinged case; gold and steel examples || Manual chronograph; published dimensions and attribution vary || One side-mounted button; white-enamel, silvered and black dials documented
+|}
 == Antimagnetique era (mid-1930s to late 1940s) ==
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 ! Era !! Movement !! Case construction !! Pushers !! References
 |-
-| Pre-Oyster (1930s–40s) || Published descriptions conflict: 13-ligne or 14-ligne; Valjoux 22, V23 or VZ || Round snap-back, non-Oyster; no inner-case specification established here || Two; oval/olive or rectangular || [[Reference:2508|2508]]
+| Early monopusher (1920s–30s) || Case-specific descriptions vary; no shared caliber assigned || Round, hinged, non-Oyster; 39–41mm examples || One side button || [[Reference:2021|2021]]
+|-
+| Non-Oyster two-pusher (1930s–40s) || Published descriptions conflict: 13-ligne or 14-ligne; Valjoux 22, V23 or VZ || Round snap-back, non-Oyster || Two; oval/olive or rectangular || [[Reference:2508|2508]]
 |-
 | Monoblocco Oyster (1939–1946) || Rolex Cal. 13 (Valjoux 23 VZ) || One-piece upper case, screw-down caseback || Pump || 3525, 3668, 3833