Reference:Movements

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Rolex movements

Every caliber below powered a reference documented on this wiki. Each gets its own entry: specification woven into the history rather than boxed off in a table, the visual and finishing details that let a collector recognize a genuine example, and a photograph where one has been sourced and verified. Fitment is kept to a representative reference or two rather than an exhaustive list — the individual reference pages carry the full case-by-case detail.

The caliber number is engraved on the movement itself and read with the caseback off; it is separate from the case serial, which is the number that dates the watch on the serial-number page. Where a movement number and case number diverge sharply, as on the stockpiled Prince calibers, the movement was made well before the case it sits in.

Prince (shaped movements)

The Prince family runs on Aegler shaped movements that predate every other Rolex caliber on this page. The 1927 Wilsdorf-Aegler patent for a "shaped watch movement with a seconds dial" placed the winding barrel at one end of the rectangular movement and the balance at the other — the architectural choice that allowed both a larger balance wheel for precision and a larger mainspring barrel for power reserve than competing shaped calibers of the period. Aegler was a supplier, not a subsidiary: the firm manufactured independently in Bienne until Rolex bought it from the Borer family in April 2004. "Aegler" and "Rebberg" name the same manufacturer — Aegler the company, Rebberg the Bienne street address. Aegler also supplied Gruen, which sold the architectural sibling of Cal. 300 in the US market as the Techni-Quadron under its own Cal. 877 designation; a Gruen-stamped movement inside a Rolex Prince case is a documented transplant pattern, and "Cal. 877" listed as a Prince caliber in some literature is a misattribution traceable to that sibling relationship.

Movement grading across the family runs Prima → Extra Prima → Ultra Prima, rising through jewel count, adjustment positions, and chronometer testing rigour. A "Chronometer" or "Observatory" mark on a Prince dial corresponds to Extra Prima or Ultra Prima grade only — a Prima movement never earns it. Rolex submitted Prince movements to the National Physical Laboratory at Kew for rate certificates independent of the Swiss Bureaux Officiels Suisse de Contrôle; the 1914 Class A Kew certificate Rolex commonly cites as its first official chronometer rating actually belongs to an earlier ladies' wristwatch movement, predating the Prince family, though the Princes continue that Kew-Teddington testing tradition from 1928 forward.

Cal. 300

Cal. 300, Extra Prima grade, rectangular Prince architecture, Bonhams lot photo

Cal. 300 is the original Prince movement, 1928 to 1935, and the architecture every other Prince caliber on this page descends from: rectangular plates, 7½ × 14½ lignes, an 18,000 vph lateral lever escapement, and roughly 50 hours of reserve. It came in three grades — 15 jewels at Prima, 18 at Extra Prima and Ultra Prima with 6-position adjustment — and the photographed example, an Extra Prima marked "Observatory 6 Positions," shows the grade tier stamped directly onto the bridge rather than left to the dial text alone. The winding-stem bridge is Cal. 300's known service fail point: a Prince that sets the time and then immediately disengages is symptomatic of a broken bridge, not a deeper fault, and aftermarket CNC-machined brass replacement bridges and stems circulate among watchmakers as a routine repair part. Rolex documented seven further commercial designations on this same architecture — 414, 527, 579 T, 701, 841 T, 1004, and 1759, below — each a different Aegler finishing or grading tier sold under its own number rather than a genuinely distinct movement.

Cal. 7½′′′ T.S. 300

Cal. 7½′′′ T.S. 300, marked "Rolex World's Records," "Rolex Chronometer," "18 Rubies, Ultra Prima"

The Très Soigné execution of Cal. 300, running 1932 to 1938: the same rectangular architecture built to the Ultra Prima 6-position standard, with a lateral lever escapement, monometallic balance on a micrometer regulator, Breguet overcoil hairspring, and rhodium plating. It is documented on the 1527 Railway, where the grade mix actually inverts the pattern seen on the 1490 — Extra Prima dominates the surviving 1527 population, and an 8-position "Officially Tested in Eight Ways" Ultra Prima example is the outlier at the top of the range, the highest-hammering Prince movement recorded (Mondani 2006, bamboo-bracelet 1931 example, CHF 27,140).

Cal. 310

A distinct caliber number within the Cal. 300 family, built specifically for the wedge-shaped 3361 Aerodynamic / 3362 / 3937 Prince group: 7½′′′ rectangular, lateral lever escapement, Superbalance adjusted to 6 positions, Breguet hairspring, swan-neck micro-regulator, available in both sub-seconds and centre-seconds form (the 3361 family takes the centre-seconds variant). Every documented 3361 catalogue entry names Cal. 310 specifically rather than folding it into the generic "Cal. 300 family" label auction houses sometimes use — that shorthand is an under-specification, not a separate sub-caliber. Production ended in 1938, but Aegler kept stockpiling movements that Rolex cased into 3361 production through 1952; a 1952-cased example with a movement number far lower than its case number is the stockpile pattern showing up directly in the serial record.

Cal. 360 HW

Cal. 360 HW, marked "Rolex, 15 Rubies, Swiss Made"

The 1936-onward successor to Cal. 300, running late-period 971, 1490, 1862, and 3361 production: tonneau-shaped movement plates in place of Cal. 300's rectangular ones, still 15–18 jewels at 18,000 vph with roughly 50 hours of reserve, Extra Prima grade. The plate-shape swap is the cleanest visual authentication tell in the whole Prince family — a 971 or 1490 with rectangular plates is a 1928–1935 example, the same case reference with tonneau plates is 1936 or later, and no dial text or case reference needs to be read to make the call.

Cal. 414

Same Cal. 300 rectangular architecture, 15–17 jewels, documented on 1862 cases from the early 1930s under its own commercial number rather than a distinct movement design.

Cal. 527

Circa 1934, 15–17 jewels, the same architecture again. The canonical documented example is a Christie's Watches Online lot, a 9K Prince 1862 from Glasgow with a "Modèle déposé" enamel-marked dial.

Cal. 579 T

Circa 1935, 15–17 jewels, documented on a collector-market 1862. The "T" suffix likely marks a specific Aegler finishing or adjustment tier within the family rather than a separate architecture.

Cal. 701

Mid-1930s, 15–17 jewels, documented on 1862 cases — another commercial number on the same Cal. 300 base.

Cal. 841 T

Circa 1930, 17 jewels, documented on a Bonhams-catalogued 1862. Like Cal. 579 T, the "T" suffix denotes an Aegler grading tier rather than a distinct movement.

Cal. 1004

Circa 1936, 17 jewels, documented on a Christie's London 9K Glasgow 1862 catalogued as "officially tested in 8 positions" — an unusual adjustment count, since Swiss and Kew chronometer protocols typically test 5 or 6 positions, which suggests an Aegler-internal regulation tier rather than a formal Bureaux-Officiels-Suisse-de-Contrôle certification.

Cal. 1759

Cal. 1759, "1759, 18 RUBIES, ULTRA PRIMA," with its matching case back

The Ultra Prima Chronometer execution, circa 1937: 18 jewels, 6-position adjustment, documented on a 9K Prince 1862 from Glasgow. The photographed example pairs the movement with its original case back, engraved "1759, 18 Rubies, Ultra Prima" alongside "31 Records Universels" and the retailer stamp — a rare survival of movement and original case together. Auction catalogues have used both "Cal. 300 Ultra Prima" and "Cal. 1759 Ultra Prima Chronometer" for architecturally identical specs; the caliber-number drift between houses is documented but not fully resolved.

Cal. 971A

The late commercial designation in the Cal. 300 family, circa 1938–1952: lateral lever escapement, Superbalance, Breguet hairspring, 6–7 position adjustment, 18 jewels. Documented on the 3937 Rams Horn in 14K rose gold. The "971A" letter suffix follows Aegler's convention of using letters for finishing tiers, distinct from the family-level "Cal. 300" shorthand some catalogues substitute for it. Dealer listings occasionally attribute Cal. 1530 to the 3937 — that is a straightforward misattribution, since Cal. 1530 is a 1965-era Oyster Perpetual caliber that did not exist when the 3937 was in production.

Two further notes apply across the whole family rather than to one caliber. The 1491 Brancard Jumping Hour adds a jump-hour module to the rear of a standard 7½′′′ Extra Prima Observatory base (Phillips labels the base Cal. 350 T.S.) — there is no separate caliber number for the module itself, and the extra mechanical thickness it needs is why the 1491 case runs deeper than the 1490's; that case-depth difference is the canonical way to catch a 1490 retrofitted with a later module and passed off as a genuine 1491. Three module-specific service patterns turn up in the collector record: a weak jump-impulse spring producing a "lazy" disc advance, a worn disc-retention pawl producing hour-disc jitter, and a misaligned dial aperture that reveals fragments of two numerals at once.

Bubbleback and early automatic

Bubbleback and early Oyster Perpetual references run on a distinct family of early self-winding calibers, separate from the Prince's manual shaped movements and predating the standardized post-war automatic line. The "bubble" in Bubbleback describes the domed caseback these movements needed to clear their automatic rotor — a genuine self-winding mechanism, not a bumper system, at a time when most competing automatics still used one.

Cal. 520

The first Bubbleback caliber, debuting in the original 1933 reference 1858 with its three-piece Oyster case: automatic, 19 jewels, 18,000 vph. Documented on the 3353 by case description. Superseded by Cal. 620 as the movement architecture matured through the mid-1930s. No individually-confirmed movement photograph has surfaced for this caliber yet — treat any generic "early Bubbleback movement" image with a 520 label with caution unless the caliber number is actually visible engraved on the piece.

Cal. 620

Cal. 620, EmmyWatch

11½ lignes, 26.4mm diameter, 7.5mm height, 17 jewels, 18,000 vph, 35 hours of reserve, derived from the manual-wind Cal. 600. The rotor is the defining feature: a uni-directional "Perpetual" weight that spins a full 360 degrees with no bumpers or buffers, at a time when competing automatics still relied on bumper systems. It's engraved "ROLEX PERPETUAL / CHRONOMETER / SWISS MADE / PATENTED / SUPER-BALANCE," and an 18mm cover plate held by three screws carries its own "VIS TIRETTE / PATENTED / TRIGGER SCREW" marking. Cal. 620 powered the original 1931 "Perpetual" and the early Bubbleback generation, and is the base architecture Cal. 630 (and the related 635, 645) evolved from directly.

Cal. 630

Cal. 630, EmmyWatch

Evolved directly from the Cal. 620 base — Caliber Corner groups 620, 630, 635, and 645 as one related family — typically 17 jewels at 18,000 vph. A full independent specification distinct from 620's hasn't surfaced in the sources checked so far; treat jewel count and dimensions as provisional until a dedicated primary source turns up.

Cal. 10½ Hunter

An Aegler-supplied 10½-ligne hand-wound family (700 / 710 / 720 base architecture) rather than an automatic: 15 jewels early, 17 later, 18,000 vph, non-chronometer, central seconds. It powers the originating Air-King 4925 and its Air-Lion / Air-Tiger / Air-Giant siblings — the 4365 sub-seconds, 4444 mid-size, and 4647 Hunter Precision — through 1945–53, sitting architecturally between the pre-war Prince and Bubbleback shaped calibers and the post-war 1030 automatic.

Cal. A260

Cal. A260-era movement, engraved Rolex Self Winder, Jewels, Patented

1953–55, 19 jewels, 18,000 vph, 36 hours of reserve, 26.4mm — the caliber in the first Submariner references, 6204 and 6205. Its rotor is "non-butterfly," visually distinct from the butterfly-rotor Cal. 1030 that follows it. Hodinkee describes A260 as repurposed from earlier Oyster Perpetual models including later Bubblebacks, rather than a clean-sheet design for the Submariner.

Cal. A296

Cal. A296-era rotor component, engraved Rolex Perpetual Chronometer

1952–55, 18 jewels, 18,000 vph, 36 hours, 29.5mm, a full-rotor uni-directional Perpetual — genuinely not a bumper caliber, despite sometimes being described as one, a confusion with Bubbleback-era geometry. A296 powers the Big Crown 6200 and the earliest Explorers, with the 6150 "Precision" and 6350 chronometer references showing the identical movement in non-COSC and COSC form. Cal. 1030 succeeds it from 1955 with bidirectional winding via a butterfly rotor and a thinner autowind module; that thickness reduction is specifically what eliminates the domed Bubbleback caseback profile going forward — Phillips' Geneva Watch Auction FOUR framed the A296-to-1030 swap explicitly as a thickness change, not a different winding concept.

Vintage sport calibers (Submariner, GMT-Master, Explorer, Air-King)

The sport time-only and GMT line runs through three broad chapters: the A-series and Cal. 1030 opening generation above, a long 15xx-family middle chapter, and the GMT branch's own parallel thread through the bakelite-bezel era. The 15xx family anchors Rolex's longest-running production stretch — Cal. 1530 through the early 1960s, Cal. 1520 as its permanent non-chronometer twin, and Cal. 1560/1570 carrying the chronometer side of Submariner, GMT-Master, and Explorer production into the 1980s.

Cal. 1030

Cal. 1030, engraved "1030," 25 jewels, butterfly rotor

Rolex's first bidirectional automatic, 1950–62, 25 jewels, 18,000 vph, 42 hours, 28.5 × 5.85mm — the caliber that ends the domed-caseback era. Its "butterfly" rotor, named for its cutaway wing-like shape, is stamped ROLEX PERPETUAL PATENTED and is the single most recognizable identifier for the caliber; perlage finishing on the rhodium-plated mainplate, brushed (not striped) bridges, polished screw heads, and red anodized-aluminum reversing wheels round out the finishing. Regulation runs on a traditional pinned index rather than free-sprung Microstella — a visible regulator arm near the balance is the fastest way to tell a 1030 apart from its free-sprung 1560/1570 successors at a glance. It first appears on the 6098 in 1952, running through the 6536, 6536-1, and 6538 Submariners, the 6610 Explorer, and the 6552 Air-King, in both COSC and non-COSC form on the identical movement, and represented Rolex's first fully in-house automatic — no external ébauche supplier — with a 5.85mm profile thin enough to leave the bubble-caseback era behind for good.

Cal. 1530

Cal. 1530-era butterfly rotor halves, Rolex coronet stamped

1957–65, 17 jewels early rising to 25 then 26 late, 18,000 vph, 44 hours. Traditional Swiss lever escapement with a 15-tooth club-tooth wheel, screwed Glucydur balance. The rotor shape evolves mid-production from butterfly to half-moon, and later runs add blued screws on the auto-winding bridge with red Teflon-coated gears replacing brass — both genuine dating markers for a given example. First Submariner appearance is the 5510 in 1958–59, not yet chronometer-rated; chronometer certification arrives with Cal. 1560 on the 5512 instead. It also powers the 36mm Explorer-case 5504 Air-King alongside the early 5500 production, and Bonhams has catalogued it in a 1002 and a 1003 against the Watch-Wiki concordance that assigns it to the 5500 family only — a documented outlier, not a confirmed cross-reference pattern. Cal. 1530 was deliberately never COSC-certified across most of its run: regulating a labor-intensive screwed balance to chronometer tolerance at Rolex's production volume was judged uneconomical, a cost decision rather than a technical shortfall.

Cal. 1520

Cal. 1520, engraved "1520," EmmyWatch

The permanent non-chronometer twin of Cal. 1530, 1963–90, 17/25/26 jewels at 19,800 vph — the 17-jewel variant is a US/Canada import-duty-bracket move, not a different movement. It powers late 5513, 5514, and 5517 Submariners and the long-running 5500 Air-King from 1963 onward, plus the 1002 Oyster Perpetual, 5501, and 5520.

Cal. 1525

Cal. 1525, EmmyWatch

A date-module variant of Cal. 1520, 1959 to c.1975, 17/25 jewels, powering the early 5700/5701 Air-King-Date at the non-chronometer "Precision" tier. The chronometer-rated date option in this generation runs on a related 1500-series caliber instead, in the 1500/1501/1503/1505 Oyster Perpetual Date.

Cal. 1535

Cal. 1535, EmmyWatch

The later running update to Cal. 1525, c.1975–1988, 26 jewels, same date-module architecture, non-chronometer, carrying the 5700/5701 Air-King-Date through its final production years.

Cal. 1560

Cal. 1560, EmmyWatch

1959–65, 26 jewels, 18,000 vph, 42 hours, the cross-family chronometer bridging Cal. 1530 and Cal. 1570 architecturally: it gains jewels over the 1530 and, like the 1570 after it, carries COSC certification, without yet reaching the 1570's higher 19,800 vph beat rate. Powers mid-production 5512, 1675, and 1016.

Cal. 1565

Cal. 1565, EmmyWatch

1959–65, 25 jewels, 18,000 vph, 42 hours, the "caller" GMT caliber in the early 1675 — 24-hour hand still linked to the main hour hand rather than jumping independently, the layout the whole GMT branch carries until Cal. 3085 breaks the pattern decades later.

Cal. 1570

Cal. 1570, open caseback

1965–80, 26 jewels, 19,800 vph, 44 hours, 28.5 × 5.75mm — the higher-beat successor to Cal. 1560, with hacking added mid-life. Free-sprung Breguet hairspring with screw-based poising, two Microstella screws for regulation, Kif Ultraflex shock protection. It runs across the Submariner and Explorer lines through the late 1970s, and dealer listings that describe a "1500" as carrying Cal. 1575 are often actually describing a 1570 — reference confusion the movement, not the dial text, resolves.

Cal. 1575

Cal. 1575, EmmyWatch

1965–80, 25 jewels, 19,800 vph, 50 hours — adds either a date module or a GMT module onto the 1570 base, which is how the same caliber number lands on the 1680 (date), the late 1675 (GMT), and the 1655 Explorer II (GMT with 24-hour bezel) simultaneously.

GMT-Master line

The GMT branch reads in three distinct steps rather than a single continuous upgrade path. Cal. 1036 and 1065 belong to the bakelite-bezel 6542 era and keep the 24-hour hand synchronized to the main hour hand. Cal. 1565, 1575, and 3075 carry that same synchronized "caller" layout through the 1675 and 16750 generation. Cal. 3085 then breaks the pattern with the GMT branch's first independently jumping local hour hand, and Cal. 3175 keeps the older synchronized layout alive in parallel on the 16700 until 1999 even as Cal. 3185 and 3186 define the long 16710 run that follows.

Cal. 1036

Cal. 1036, EmmyWatch

1954–59, 25 jewels, 18,000 vph, 42 hours — the first GMT caliber, in the bakelite-bezel 6542. Rotor and bridge spell out "TWENTY FIVE JEWELS" in full rather than abbreviating it, an early-production engraving convention that helps date a given example.

Cal. 1065

Cal. 1065, EmmyWatch

1956–59, 25 jewels, 18,000 vph, 42 hours, the late-6542 GMT caliber succeeding Cal. 1036 within the same bakelite-bezel generation.

Cal. 3075

Cal. 3075, engraved "3075," EmmyWatch

1979–88, 27 jewels, 28,800 vph, 48 hours, hacking, quickset, chronometer — carries the synchronized "caller" GMT layout into the 16750/16753/16758 generation.

Cal. 3085

Cal. 3085, EmmyWatch

1983–89, 27 jewels, 28,800 vph, 48 hours, hacking, chronometer, 28.5 × 6.3mm. The first Rolex caliber to dissociate the local-hour hand from the 24-hour hand: local hour sets independently in one-hour clicks while the 24-hour hand tracks the bezel for a third time zone, at the cost of losing quickset date, which now advances only via the local-hour hand. Its 6.3mm thickness directly drove the 16760 "Fat Lady" / "Sophia Loren" case proportions, and it ran exclusively in the 16760 GMT-Master II and the 16550 Explorer II.

Cal. 3130

Cal. 3130, engraved "3130," EmmyWatch

1999–2018, 31 jewels, 28,800 vph, 48 hours, hacking, chronometer — the time-only successor to Cal. 3000, carrying the 14060M, 114060, 114270, and 114200 through the 2000s and 2010s.

Cal. 3132

Cal. 3132

2010–c.2020, 31 jewels, 28,800 vph, 48 hours, hacking, chronometer — Cal. 3130 with a Parachrom hairspring and Paraflex shock system added, powering the 214270 Explorer.

Cal. 3175

Cal. 3175, EmmyWatch

1988–99, 31 jewels, 28,800 vph, 48 hours, hacking, quickset, chronometer, adjusted to 5 positions and temperature, Glucydur balance with Microstella, Breguet hairspring, Kif shock. The last "caller" GMT and the last fixed-GMT caliber Rolex built, running in a single reference, the 16700 — the 24-hour hand stays linked to local hour, and the second time zone reads off the bezel rather than an independent hand, keeping the older synchronized layout alive right up to 1999 even as the rest of the GMT line had already moved on to the jumping-hour Cal. 3185.

Cal. 3185

Cal. 3185, engraved "3185"

1989–c.2007, 31 jewels, 28,800 vph, 48 hours, hacking, quickset, chronometer, KIF Elastor shock. Derived directly from the Cal. 3135 platform with an added 24-hour GMT hand mechanism, powering the 16710, 16713, 16718, and 16570. Both Microstella nuts are always adjusted identically as a pair, a documented service note to avoid poise imbalance. At 6.45mm it's noticeably slimmer than the 7.2mm Cal. 3085 it replaced, part of why the 16710 case reads thinner on the wrist than the earlier "Fat Lady" 16760.

Cal. 3186

Cal. 3186, engraved "3186"

2007–19, 31 jewels, 28,800 vph, 50 hours, hacking, quickset, chronometer — adds a Parachrom hairspring to the Cal. 3185 base, carrying late 16710 production into the ceramic-bezel GMT line, the 116710LN, 116710BLNR, and 116719BLRO.

Modern sport calibers (1988–2020)

The modern time-only line settles on the 31xx family, opening with Cal. 3000 as the first 28,800 vph no-date movement of the era and running through Cal. 3130 and 3132 in direct succession. Cal. 3135, the date-equipped counterpart introduced the same year as Cal. 3000, becomes the single dominant modern Rolex workhorse across three decades of Submariner Date production.

Cal. 3000

Cal. 3000

1989–99, 27 jewels, 28,800 vph, 42 hours (some owners report 45–60 hours in practice), 28.5 × 5.8mm — the first 28,800 vph time-only movement of the modern era, based on Cal. 3035 and powering the 14000 Air-King, 14010, 14060 Submariner, and 14270 Explorer. Deliberately simplified against the outgoing 1570 generation: a flat hairspring with no Breguet overcoil, and an adjustable-mass balance with no separate regulator arm at all. The automatic-winding module runs oversized components, including PTFE-coated red-alloy click wheels, and watchmakers commonly single out the winding module as the best-finished part of an otherwise deliberately economical movement.

Cal. 3035

Cal. 3035, engraved "3035," EmmyWatch

1977–88, 27 jewels, 28,800 vph, 48 hours, hacking, quickset, chronometer — the first quickset Submariner caliber, in the 16800, 168000, 16808, and 16803.

Cal. 3135

Cal. 3135, official Rolex photo, engraved "3135," 31 jewels

1988–2018, 31 jewels, 28,800 vph, 48 hours, hacking, quickset, chronometer — Rolex's 30-year workhorse, running the 16610, 16613, and 16618 through to the 116610 generation. Rhodium-plated finish, beveled and polished chamfered screws, a two-piece axle-style bidirectional rotor, and four Microstella nuts for regulation that need a dedicated Microstella key. The reversing wheels (Rolex part 32135-540) are anodized purple-red and visible straight through the rotor cutout — an easy, no-disassembly identification marker. The hairspring material switched from Nivarox to Parachrom Blue circa 2007–2008, a running production change collectors use to help date an individual movement without opening the case.

Daytona chronograph (manual-wind)

The manual-wind Daytona stays on Valjoux 72 architecture for its entire first chapter, 1963 through 1988, moving through five caliber numbers as Rolex progressively finished and then re-rated the same base ébauche.

Cal. 72

1960–65, 17 jewels, 18,000 vph, 48 hours — a bare Valjoux 72 with minimal Rolex finishing, in the 6234 and earliest 6238.

Cal. 72A

Early-to-mid 1960s, 17 jewels, 18,000 vph, 48 hours — a Rolex-finished intermediate step between Cal. 72 and 72B; thinly documented in the collector record.

Cal. 72B

Rolex-signed Valjoux 72-family movement, seventeen jewels — caliber sub-variant not distinguishable from the engraving alone

1962–65, 17 jewels, 18,000 vph, 48 hours — the final pre-722 Valjoux 72 execution, in the early 6238.

Cal. 722

Rolex-signed Valjoux 72-family movement, seventeen jewels — caliber sub-variant not distinguishable from the engraving alone

1963–69, 17 jewels, 18,000 vph, 48 hours — the first Rolex-stamped Valjoux 72, powering the original 6239 alongside the 6240 and 6241 generation, the run that includes the "Paul Newman" dial variants.

Cal. 722-1

Rolex-signed Valjoux 72-family movement, seventeen jewels — caliber sub-variant not distinguishable from the engraving alone

1969–70, 17 jewels, 18,000 vph, 48 hours — a transitional revision of Cal. 722 bridging into the higher-beat Cal. 727 era.

Cal. 727

Cal. 727 (right, engraved 727, Daytona ref 6265), specialist comparison photo via Perezcope

1970–88, 17 jewels, 21,600 vph, 48 hours — the higher-beat Valjoux 72 that lifts the rate from 18,000 to 21,600 vph and runs through the 6262, 6263, 6264, and 6265 until the manual-wind Daytona era closes in 1988. The photographed comparison — a specialist side-by-side of two period movements, one catalogued as a "Rolex Daytona Ref. 6263" in quotation marks, the other a confirmed genuine 6265 with "727" plainly engraved — is itself a useful authentication reference: matching a movement's actual engraved caliber number against what a listing claims is exactly the kind of check that separates a documented example from a franken watch.

Daytona chronograph (automatic)

Cal. 4030

Cal. 4030, engraved 4030, thirty-one jewels

1988–2000, 31 jewels, 28,800 vph, 54 hours, chronometer — Rolex's most disputed movement specification, and the last foreign-sourced caliber in its modern line. The working outline is a heavily reworked Zenith El Primero base, launched with the 16520 for a twelve-year run; serious sources agree on the 28,800 vph rate, a free-sprung Breguet balance, and no date function, but diverge on the exact length of Rolex's modification list and quote the power reserve as either 52 or 54 hours depending on source. The photographed example, marked "MONTRES ROLEX S.A. GENEVA SWISS, ADJ. 5 POSITIONS TEMPERATURE, THIRTY-ONE JEWELS" with "4030" in a small stamped box, is a clean confirmation of the caliber regardless of which modification-list version a given source favors.

Cal. 4130

Cal. 4130 movement detail, bridge marked "4130"

2000–present, 44 jewels, 28,800 vph, 72 hours, chronometer — Rolex's first fully in-house chronograph movement, launched with the 116520. Column-wheel construction with a vertical clutch, 201 components, and the first Rolex chronograph to run on a ceramic ball-bearing rotor (7 balls on 3 screws) rather than a sleeve bearing, cutting the part count below the Cal. 4030 it replaced despite the added complexity. Solid caseback only — the display back arrives with the 4131 successor in 2023 — and the vented rotor carries a proprietary Rolex striping pattern, a visual tell against generic aftermarket rotors sometimes swapped into grey-market builds. It powered the whole pre-ceramic in-house Daytona generation and carried forward into the 116500LN.

Day-Date

The Day-Date runs on its own caliber family, entirely separate from the sport and Oyster Perpetual movements documented above. Quickset arrives only with the 5-digit generation — every 4-digit Day-Date sets the day and date exclusively by running the hands through midnight.

Cal. 1055

Cal. 1055, period parts-catalogue illustration, front and back

1956–1959, 25 jewels, 18,000 vph, 42 hours — Rolex's first day-and-date caliber, carried by the originals-era 6510, 6511, 6611, 6612, and 6613. The generation-1 movement (6510/6511) pre-dates COSC certification; the generation-2 "1055B" (6611/6612/6613) adds a free-sprung Microstella balance, Breguet overcoil, and full COSC rating. Rhodium-plated three-bridge design with Côtes de Genève on the bridges. The 1055B upgrade is also a dial-text tell: it's the first Rolex caliber associated with "Superlative Chronometer Officially Certified" wording, replacing the "Officially Certified Chronometer" script the generation-1 dials carried. No quickset, no hacking, on either generation.

Cal. 1555

Cal. 1555, rotor bridge detail

1959–c.1965, 25 jewels, 18,000 vph, 42 hours, chronometer, still non-quickset and non-hacking — a Cal. 1055-derived movement carrying the early 4-digit Day-Date (1803, 1804, 1806, 1807, 1811). Free-sprung beryllium-bronze balance with four gold-toned Microstella regulation nuts visible on the balance rim, the clearest visual break from the pinned-regulator 1030/1530 generation running in parallel on the sport watches. Height grew to 7.03mm to house the day-disc mechanism, and early production (1959 to c.1970) pairs with the stepped "pie-pan" dial profile collectors track as a separate variant.

Cal. 1556

Cal. 1556

c.1965–1977/78, 26 jewels, 19,800 vph, 42 hours, chronometer, still no quickset — a higher-frequency successor to Cal. 1555, carrying the mid-and-late 4-digit Day-Date (1803, 1804, 1806, 1807, 1811). Hacking was added mid-production in 1972; examples built before that date do not hack, a genuine running change rather than a running fault.

Cal. 3055

Cal. 3055, period parts-catalogue illustration with day-disc

1977–1988, 27 jewels, 28,800 vph, 48 hours, hacking, chronometer — the first Day-Date caliber with any quickset at all, though only for the date; the day still advances by running the hands. Sapphire-crystal era, carrying the 18038, 18048, 18078, and early 18238. The day-disc mechanism sits visibly on the dial-side plate, distinct from the rotor-side bridge finishing shown on the earlier 1055/1555/1556 generation.

Cal. 3155

Cal. 3155, engraved "3155," EmmyWatch

1988–2019, 31 jewels, 28,800 vph, 48 hours, hacking, chronometer — adds the day quickset that Cal. 3055 lacked, the double-quickset the 18238 introduced and the long-serving movement that carried the 6-digit 118238 family for three decades.

Cal. 3156

Cal. 3156, engraved "3156," Day-Date II official brochure image

2008–2015, 31 jewels, 28,800 vph, 48 hours, hacking, double quickset, chronometer — a Cal. 3155 derivative built for the 41mm Day-Date II, with a Parachrom hairspring and Paraflex shock added, powering the 218238, 218239, 218206, and 218235.

Oysterquartz

The Oysterquartz sits outside the mechanical line entirely: Rolex's own in-house quartz calibers, launched in 1977 and run through 2001, with total output staying small — under about 25,000 watches across the full 24-year production span.

Cal. 5035

Cal. 5035, engraved "5035," "11 ELEVEN JEWELS," "1.55V," EmmyWatch

1977–2001, 11 jewels, hacking, quickset, chronometer, running on a 1.55V cell — powers the Oysterquartz Datejust and Oyster Perpetual references, including the 17000, 17013, and 17014.

Cal. 5055

Cal. 5055, engraved "5055," "11 ELEVEN JEWELS," EmmyWatch

1977–2001, 11 jewels, hacking, quickset, chronometer — the Day-Date counterpart to Cal. 5035, powering the Oysterquartz Day-Date 19018 in yellow gold and 19019 in white gold, plus the pyramid-bezel 19028.

Related but not Rolex

Two commonly-confused calibers turn up in Prince and Bubbleback research but aren't Rolex movements at all. Gruen's Cal. 877, used in the Techni-Quadron, is the Aegler architectural sibling of Cal. 300 sold under Gruen's own brand for the US market — the shared supplier explains the identical layout, but it was never a Rolex commercial number. And any Bubbleback-era "9¾ ligne" or "9¾ lignes" note on a reference page means only that the movement's size class was documented, not the specific caliber number — a real gap in the source, not a claim that a distinct "9¾ ligne caliber" exists as its own entry.

Sources

• Revolution — A Movement in History: The Zenith-driven Rolex Daytona (Ross Povey, 2018)
• Hodinkee — A Vintage Watch Nerd's Critical Dissection of the Rolex Daytona, Part 1 (Paul Boutros, 2012)
• Hodinkee — A Vintage Watch Nerd's Critical Dissection of the Rolex Daytona, Part 2 (Paul Boutros, 2013)
• Monochrome — In-Depth: The History of the Rolex Daytona (Erik Slaven, 2024)
• Monochrome — History of the Rolex Submariner, Part 1 (Tom Mulraney, 2020)
• Monochrome — History of the Rolex Submariner, Part 2 (Tom Mulraney, 2020)
• Monochrome — In-Depth: The History of the Rolex GMT-Master and GMT-Master II
• Monochrome — The History of the Rolex Explorer (Frank Geelen, 2024)
• Monochrome — In-Depth: The History of the Rolex Explorer II
• Monochrome — Youngtimer Case Study, the Rolex Explorer 14270 (Frank Geelen, 2020)
• Monochrome — Rolex Explorer 214270 In-Depth Review (Brice Goulard, 2016)
• Hodinkee — A Comprehensive Collector's Guide To The Rolex Explorer I (Jon Bues, 2022)
• WatchTime — Tracking the Rolex Daytona: A 55-Year History
• Revolution — The Rolex "John Player Special" Paul Newman Daytona Ref. 6241 (Bob Ridley, 2017)
• A Collected Man — Is the Rolex Pre-Daytona a Forgotten Classic? (Russell Sheldrake, 2020)
• Fratello — Why I Bought The Rolex Cosmograph Daytona Reference 116520 (Ben Hodges, 2021)
• Fratello — Rolex Submariner 14060M Review
• Fratello — Rolex Submariner 114060 Review (2019)
• Fratello — Ceramic Bezel close-up of the Rolex GMT-Master II ref. 116710LN
• Sotheby's — Submariner Ref 6536/1, Stainless Steel Automatic With Bracelet, Circa 1957
• Sotheby's — Submariner Ref. 6538, Stainless Steel With 4-Line Tropical Dial, Circa 1958
• Caliber Corner — per-caliber technical database
• EmmyWatch — vintage restoration movement photography
• The Vintage Rolex Field Manual — Colin A. White, Morning Tundra