ETA 2824: The History and Legacy of a Legendary Workhorse Caliber

The ETA 2824 caliber has been a presence in the world of mechanical wristwatches for more than 50 years, helping the Swiss watchmaking industry forge a path through the Quartz Crisis and serving as the engine for hundreds of three-handed timepieces from an array of brands, large and small. While it is a rarity here in the 21st Century, its legacy can still be seen across the horological world — from the proliferation of similar movements by makers like Sellita to the increasing ubiquity of the ETA 2824’s souped-up successor, the Powermatic 80. Read on to learn everything you need to know about the ETA 2824.

A (Very Brief) History of ETA

Nearly everyone that follows the wristwatch industry has heard of ETA, and most of those have probably worn a watch with an ETA movement, but few are likely aware of the Swiss movement maker’s long and convoluted history. We generally trace its origins back to the formation of the historical watchmaking firm Eterna, in 1856 in the Swiss town of Grenchen. But in reality its roots reach even deeper.

Eterna is perhaps most famous today as the maker of the Kon-Tiki dive watch, and it is currently owned by the Hong Kong-based Citychamp Watch and Jewellery Group. Originally however, the firm was a manufacturer of ébauches — unassembled movements for sale to outside watchmakers — and was named “Dr. Girard & Schild” for its founders, Dr. Joseph Girard and Urs Schild. Renamed Schild Frères by the next generation of owners, the company (which took the name Eterna in 1906, adopting the name of one of its products) started producing wristwatches in the early 1900s and, by 1932 had split off a subsidiary called ETA SA as a movement maker, both for itself and for outside clients in the watchmaking business.

A flurry of mergers and consolidations, among an alphabet soup full of companies, was already well underway in the Swiss watch industry during this challenging economic period, and they all played a role in forming the ETA of today. The most impactful of these was the formation of Ébauches SA in 1926, which merged three of the largest movement and component manufacturers in Switzerland, including A. Schild SA (or ASSA, and to make things even more confusing, not associated with Schild Frères); the Fabriques d’Horlogerie de Fontainemelon, or FHF, established even earlier, in 1793; and Adolphe Michel SA (AMSA), established in 1898. The reason that Eterna had to spin off its movement making operation into a separate company was because Ébauches SA was made up only of movement producers, not watchmakers, and joining this conglomeration, as it did in 1932, was the only way for ETA SA to survive the turbulent economic times that were on the horizon. 

Ébauches SA had been continually expanding in the years since its founding, bringing more independent shops under its roof, and in 1931 it became a founding member of ASUAG (Allgemeine Schweizerische Uhrenindustrie AG ) a huge holding company that was formed by Switzerland’s government and banking industry in response to the Great Depression. ASUAG merged with another conglomerate, known as SSIH (Societé Suisse pour l’Industrie Horlogère, which included heritage watchmakers like Omega and Tissot and the legendary movement maker Lemania) in 1983 to form what was originally called SMH (Societé de Microélectronique et d’Horlogerie) and which was eventually renamed the Swatch Group. In a nutshell, this is how Eterna’s movement-making arm became part of the Swatch Group and eventually, owing to the near-monopoly on equipment and expertise that it had built up since the Ébauches SA days, eventually became the largest and most prolific movement supplier in all the Swiss watch industry. 

From Eterna 1427 to ETA 2824

The movement that is regarded as the foundation for the ETA 2824 is Eterna’s Caliber 1427, introduced in 1955. It was a descendant of Eterna’s original “Eterna-Matic” movements, which debuted in 1948 and were notable for their ultra-efficient design that used five strategically placed ball bearings to reduce friction on the winding mechanism to increase the watch’s accuracy and reliability. (The “five ball” design is so integral to Eterna’s identity as a watchmaking brand that it is even the basis of its logo.) Eterna-Matic timepieces were very popular during the decades they were produced, setting new standards for wristwatches with automatic movements. 

With the end of the 1960s, however, came the Quartz Crisis that necessitated big moves in a Swiss watch industry that was facing yet another economic downturn. One of these was the major  merger between ASUAG and SSIH to form the Swatch Group. Another Swiss response to the incursion of lower-priced, more accurate quartz calibers into the business was the development of mechanical self-winding “workhorse” movements, which could be manufactured at relatively low cost and still deliver robustness and accuracy.  The clear leader of this new generation of movements was the ETA 2824, which evolved from the Eterna 1427 and its brethren and debuted on the market in 1971. Key elements of the ETA 2824 were its relatively compact size (25.6mm diameter, 4.6mm thickness); its frequency of 28,800 vph, or 4 Hz; automatic winding provided by a rotor, centrally mounted and secured to the balance bridge by a single screw; and its uncommonly large balance wheel at 12 o’clock, whose inertia-heavy size necessitated a below-average power reserve of 38 hours. 

ETA 2824-1 and ETA 2824-2: The Next Generations

The ETA 2824 was produced from 1971 until 1979, when it was replaced and superseded by the 2824-1. That movement, which had a fairly brief production run ending in 1982, was identical to its predecessor in almost every respect but upped the jewel count from 17 to 21. (To learn more about what jewels are for in a watch movement and why they are important, check out this article). The ETA 2824 unveiled in 1982 had a much longer run, mass-produced until 2002 and still made in limited quantities today. This third-generation version boosted the jewel count to 25 and added an Incabloc anti-shock system. Its bidirectional, ball-bearing-mounted rotor achieves a minimum power reserve of 38 hours and maxes out around 42 hours. Additional modern upgrades include a nickel-plated balance wheel and an antimagnetic Nivarox hairspring. In its “standard” version, the movement has a daily accuracy of +/- 12 to 30 seconds; ETA also makes a COSC-certified version of the 2824-2 that boasts a chronometer-level precision of +6/-4 seconds per day. In its most basic form, the movement provides central hours, minutes and seconds as well as a date calendar that can be positioned on the dial in several different spots based on design needs. 

ETA 2824-2 Descendants

Which watches have housed some version of the ETA 2824 during its decades in production? More than you probably think. Breitling’s Caliber 17 (or B17) is based on the COSC-quality version of the 2824, and is found in many of the brand’s three-handed watches, including many from the Superocean family of dive watches. (More recently, Breitling has also used the “clone” Sellita SW200 as the base for some of its B17 calibers as well.) TAG Heuer built its Caliber 5 on the 2824-2 base, and uses it throughout its line, in time-only versions of its racing-inspired Carrera and inside the Aquaracer dive watches. 

Oris was a longtime user of the ETA 2824-2, and its more complicated variations, as the base for many of its recognizable “red-rotor” modified movements. More recently, Oris has employed Sellita calibers (more on which to follow) for this purpose, and has also begun installing its own in-house movements in some watches that had previously contained outsourced ETA movements.

Tudor, while it has greatly expanded its own in-house movement production, installed an ETA 2824 in the first version of its trendsetting Heritage Black Bay model and the movement is the foundation of the Tudor T601 caliber still used in some of the Rolex-owned brand's lower-tier watches. Since 2020, when ETA stopped selling the 2824-2 — and all its other movements — to companies outside the Swatch Group, Tudor has joined many other brands, including TAG and Breitling, in using the Sellita SW200 and its variants for its basic, no-frills, time-only movements, in this case the Caliber T601. 

All of these brand-modified examples are, of course, in addition to the many offspring that the 2824 has spawned within the ETA family itself. The 2804-2 is the manually winding version of the self-winding 2824-2, with fewer jewels (17) and a thinner profile (3.35mm) thanks to its lack of a winding rotor. (Hamilton's entry-level Khaki Field Mechanical models used these movements before their eventual upgrade to the "Powermatic" Caliber H-50.) Caliber 2805 strips out the date calendar for a no-date dial display, while the 2826-2, introduced in 2004, goes the other direction, adding a large date on overlapping disks at 3 o’clock. (Oris modified the 2826-2 with its distinguishing red rotor to create the Oris Caliber 643.) The 2836 version of the original caliber incorporates an indicator for both the day and date. 

ETA 2824 “Clones”

By the turn of the millennium, the ETA 2824-2 family of movements had become so widespread throughout the watch world — used not only by Swiss watchmakers but some German ones as well — that the only entity that could slow down its proliferation was ETA itself. To distill yet another long and convoluted narrative to its basic essence, the Swatch Group decreed in 2002 that it would discontinue selling ETA movements to watchmakers outside of the group, which meant that after a suitable phase-out period, the only ETA customers would be brands under the Swatch corporate umbrella, such as Longines, Tissot, Hamilton, Rado, Mido, and Certina, in addition to Swatch itself. Other brands that had long turned to ETA as a movement provider — including heavyweights like Breitling, TAG Heuer, Cartier, and IWC, among many others — would need to start producing their own in-house movements and/or find another source from which to purchase them. The year of this policy announcement, by then-Swatch Group CEO Nicolas G. Hayek, was the same year that the 20-year patent on the ETA 2824 expired. Thus, the door was now open for other enterprising movement manufacturers to legally reverse-engineer the popular movement and develop their own “clones” of it.

The first and most successful of these was Sellita, a former assembly partner of ETA that had been operating since 1950, which introduced its now-familiar SW200 caliber in 2007. The SW200 and its descendants like the SW200-1 were designed not only to copy the architecture of the 2824 calibers but to improve upon them, and most would agree that Sellita was successful in this endeavor. The SW200 features a more robust winding mechanism that is less susceptible to over-winding than its predecessor and has 26 jewels, one more than the 25 built into the ETA 2824-2. The date transition is quicker in the Sellita movement, and the detachable hour wheel and back plate makes it easier to service. With ETA’s grace period for outside watch manufacturers using its movements having expired in 2022, it is not surprising that many of these companies have embraced Sellita SW200 movements as a reliable and worthy replacement for the ETA 2824, including the major brand names noted above. 

Others who took up the gauntlet of cloning the ETA 2824 are less widely known than Sellita, which has become a movement-making powerhouse in its own right, but they include companies like STP (Swiss Technology Production), now a part of the Fossil Group, which introduced the STP1-11 in 2008 and uses it in its Zodiac watches; Soprod, another former ETA assembly partner that joined the Festina Group in 2008, which rolled out the P024 in 2022; and even China’s Seagull, which has been making its ST2130 since at least the early 2010s. If imitation is the sincerest form of flattery, ETA’s half-century-old micromechanical engine has received quite a bit of adulation from the worldwide watch industry in recent years.

Enter the Powermatic 80

As for the Swatch Group and ETA, their response to the industry-wide “cloning” of their retiring workhorse was to make a version of it that was even better in terms of efficiency, magnetic resistance, and most notably, power reserve. A remarkable technical achievement for ETA, the Powermatic 80 caliber (above, technically known as the ETA C07.111) made its debut in a Tissot watch in 2011 but has since expanded its presence to other Swatch Group brands in the more “affordable” market segment, including the aforementioned Hamilton, Rado, and Mido. To achieve its uncommonly lengthy 80-hour power reserve (most comparable movements offer power reserves around 42 hours), ETA’s engineers reduced the base ETA 2824-2 caliber’s consumption of energy by reducing the frequency of its oscillations from its longtime frequency of 4 Hz (28,800) to a more leisurely 3 Hz (21,600 vph), and added a friction-reducing synthetic material to the escapement. They also added a Nivachron hairspring for enhanced performance and shrunk the diameter of the barrel arbor’s core to allow for a stretched mainspring and thus a longer power reserve. 

Like all other ETA movements as of a few years ago, the Powermatic 80 is exclusive to the Swatch Group, and can be found in watches as diverse as the Tissot PRX and Seastar 1000 series; Hamilton's Khaki Field and Jazzmaster collections (where the movement is known as Caliber H-10);  Rado’s Captain Cook models (where it’s called Rado Caliber R734) and Mido’s Ocean Star and Multifort Chronometer (which uses the COSC-certified version of the Powermatic 80, equipped with a silicon balance spring). With the Powermatic 80, ETA reclaims its status as the maker of one of the watch industry’s most reliable and technically sound time-only movements — following along the innovative path blazed by the ETA 2824 decades earlier.