Omega watch movements: the calibre guide

Omega has made hundreds of different calibres. Eighty-two of them are documented here, grouped by family: the hand-wound 30T2, the early bumper automatics, the 5xx automatics that ran the Constellation, the 6xx that is its hand-wound sister, the chronographs fitted to the Speedmaster, and the 10xx automatics of the 1970s. Click a calibre number to open its full entry.

Calibre	Type	Jewels	Frequency	Years	Key note
30T2	Hand-wound	15	18,000 vph	1939	The original — no shock protection anywhere in it
30T2 PC	Hand-wound	15	18,000 vph	~1943	Incabloc arrives
260	Hand-wound	15	18,000 vph	1949	The 30T2 with a 1949 number on it
261	Hand-wound	17	18,000 vph	1949	Up to 17 jewels, and antimagnetic
262	Hand-wound	17	18,000 vph	1949	Chronometer grade, eccentric regulator
265	Hand-wound	15	18,000 vph	1949	Antimagnetic, Incabloc fitted
266	Hand-wound	17	18,000 vph	1950	17 jewels, antimagnetic
267	Hand-wound	17	18,000 vph	1950	A 266 in all but the number
268	Hand-wound	17	18,000 vph	~1955	Smooth-rim balance replaces the screwed one
269	Hand-wound	17	18,000 vph	1957	Flat hairspring, Novochoc shock setting
30T2 SC	Hand-wound	16	18,000 vph	1939	The RAF version
280	Hand-wound	17	18,000 vph	1949	The 30SC T2 under a new number
281	Hand-wound	17	18,000 vph	1949	Fine regulation by eccentric screw
283	Hand-wound	17	18,000 vph	1949	Sold as the Omega Century
284	Hand-wound	17	18,000 vph	1957	Two seasons only, 1957–58, so it is a scarce one
285	Hand-wound	17	18,000 vph	1958	Plain-rim balance, no screws
286	Hand-wound	17	18,000 vph	1961	Flat hairspring and Novochoc, as on the 269
330	Automatic (bumper)	17	19,800 vph	1943	First of the bumpers
331	Automatic (bumper)	17	19,800 vph	1947	Antimagnetic, chronometer grade
332	Automatic (bumper)	17	19,800 vph	1949	The 331, tidied up
333	Automatic (bumper)	17	19,800 vph	1950	Eccentric regulator version
340	Automatic (bumper)	17	19,800 vph	1943	A smaller bumper, chronometer grade
341	Automatic (bumper)	17	19,800 vph	1947	The Jubilé edition
342	Automatic (bumper)	17	19,800 vph	1949	The first Seamaster ran on this
343	Automatic (bumper)	17	19,800 vph	1950	Eccentric regulator, chronometer certified
344	Automatic (bumper)	17	19,800 vph	1953	The 342, brought up to date
350	Automatic (bumper)	17	19,800 vph	1950	Centre seconds at last
351	Automatic (bumper)	17	19,800 vph	1949	A revised version
352	Automatic (bumper)	17	19,800 vph	1950	Chronometer, eccentric regulator
353	Automatic (bumper), date	17	19,800 vph	1951	Now with a date
354	Automatic (bumper)	17	19,800 vph	1953	Swan-neck regulator on a chronometer
355	Automatic (bumper)	17	19,800 vph	1953	The last of the bumpers
550	Automatic	17	19,800 vph	1958	The base everything else is built on
551	Automatic, chronometer	24	19,800 vph	1959	24 jewels and a chronometer certificate
552	Automatic	24	19,800 vph	1959	24 jewels, no certificate — the Railmaster's
570	Automatic	17	19,800 vph	1959	One more variant in the 5xx line
571	Automatic	24	19,800 vph	1959	The 24-jewel variant
560	Automatic	17	19,800 vph	1959	The 550 with a date added
561	Automatic, chronometer	24	19,800 vph	1959	The Pie Pan Constellation calibre
562	Automatic	24	19,800 vph	1959	A 561 without the certificate
563	Automatic	17	19,800 vph	1966	The first with a quickset date; 17 jewels
564	Automatic, chronometer	24	19,800 vph	1966	Quickset date and the certificate
565	Automatic	24	19,800 vph	1966	Same as the 564, minus the certification
590	Automatic	17	19,800 vph	1960	The compact 59x series opens here
591	Automatic	20	19,800 vph	1960	20 jewels
592	Automatic	25	19,800 vph	1960	25 jewels, the most of the four
593	Automatic	17	19,800 vph	1960	Another 59x variant
750	Automatic, day-date	17	19,800 vph	1967	The day of the week joins the date
751	Automatic, day-date, chronometer	24	19,800 vph	1967	Day-date, chronometer certified
752	Automatic, day-date	24	19,800 vph	1967	The uncertified 751
321	Hand-wound chronograph	17	18,000 vph	1942–1968	The one that reached the Moon in 1969
861	Hand-wound chronograph	17	21,600 vph	1968–1996	Cheaper to build; it replaced the 321
1861	Hand-wound chronograph	18	21,600 vph	1996–2021	An 861 under rhodium plating
863	Hand-wound chronograph	17	21,600 vph	From 1985	The better-finished variant
866	Hand-wound chronograph, moonphase	17	21,600 vph	1985–1988	The first Moonwatch with a moonphase
1040	Automatic chronograph	22	28,800 vph	From 1972	Omega's automatic chronograph of the 1970s
1045	Automatic chronograph	—	—	From 1974	A Lemania 5100 at heart, not an Omega design
600	Hand-wound	17	19,800 vph	1960	The hand-wound root of the family
601	Hand-wound	17	19,800 vph	1960	The Omega hand-wound you meet most often
602	Hand-wound, chronometer	17	19,800 vph	~1960	Certified as a chronometer
610	Hand-wound, date	17	19,800 vph	1959	A 600 with a date window
611	Hand-wound, date	17	19,800 vph	1959	Date, but no quickset — set it by running the hands round
613	Hand-wound, quickset date	17	19,800 vph	1967	The most complete 6xx: quickset date
620	Hand-wound, ladies'	—	19,800 vph	1960	A ladies' calibre
625	Hand-wound	—	21,600 vph	1973	Runs at 21,600 vph
630	Hand-wound	—	19,800 vph	1962	Another variant in the line
660	Hand-wound, ladies'	17	19,800 vph	1961	Where the ladies' 66x begins
661	Hand-wound, ladies'	24	19,800 vph	1963	24 jewels
670	Hand-wound, ladies'	17	19,800 vph	1963	Ladies' calibre, 67x series
671	Hand-wound, ladies'	24	19,800 vph	1963	The 24-jewel one
672	Hand-wound, ladies', chronometer	—	19,800 vph	1968	Chronometer grade
680	Hand-wound, ladies', date	17	19,800 vph	1963	With a date
681	Hand-wound, ladies', date	24	19,800 vph	1963	Date, and 24 jewels
682	Hand-wound, ladies', chronometer	—	19,800 vph	1968	The certified one
1001	Automatic, chronometer	20	28,800 vph	1968 – 1973	The chronometer Omega had to redo
1010	Automatic	17	28,800 vph	1972	Base calibre of the 10xx
1011	Automatic, chronometer	23	28,800 vph	1972	The certified version
1012	Automatic	23	28,800 vph	1972	Far and away the commonest of the 10xx
1020	Automatic	17	28,800 vph	~1975	Where the series went next
1021	Automatic	—	28,800 vph	~1975	Yet another variant
1022	Automatic, day-date	23	28,800 vph	~1975	Day added alongside the date
1030	Hand-wound, date	17	28,800 vph	1974 – 1984	The 10xx with the rotor taken off

How to identify a vintage Omega

The calibre number is engraved on a bridge, so the caseback has to come off before you can read it. Families share architecture and parts across the range — the 30T2 was renumbered in 1949 into two branches, the 26x and the 28x, and the 6xx is the hand-wound sister of the automatic 5xx — so always work from the exact number stamped on the movement rather than from how the movement looks.