A Complete Guide to the Zenith El Primero Movement

As many of us already know, an exceptional watch is always accompanied by a dependable movement. After all, there is nothing that makes your life easier than a trusty timekeeper that looks gorgeous and provides a consistently reliable performance.

There are many brands out there with watches that possess stunning designs and highly capable movements. However, you might be surprised to find out that many of these watches actually contain the same age-defining Swiss caliber that packs a whole lot of history: the Zenith El Primero caliber. Hailing from a brand known for supplying top-notch movements to the rest of the industry, the Zenith El Primero is a revolutionary, highly versatile movement that many watchmakers have chosen to rely on, serving as a testimony to its quality. For today’s article, let us take a closer look at this iconic watch movement.

Introducing the Zenith El Primero Movement

Currently, the Zenith El Primero caliber comes in several forms. Today, we will be focusing on the El Primero Caliber 4000SC commonly found in Zenith Defy watches. The El Primero 4000SC is a modern automatic chronograph movement based on the original Zenith El Primero Caliber 400 that was released in 1969.

Much like the original caliber, the Zenith El Primero 4000SC features a power reserve that can last up to 50 hours and an impressive beat frequency of 36,000 vibrations per hour (5Hz). Held in place by thirty-one jewels, this movement has a total of 278 components, including a ball-bearing rotor made entirely out of tungsten. Apart from telling the time, the El Primero 4000SC also has chronograph, date, 30-minute, and 12-hour functions. Sticking true to the size of the first El Primero caliber, the Zenith El Primero 4000SC has a diameter of 30mm and is only 6.5mm thick.

In general, there are quite a lot of similarities between the Zenith El Primero 4000SC and the original 1969 El Primero caliber. However, one thing that Zenith has improved upon considerably is the construction of the modern El Primero caliber. Zenith constructed the El Primero 4000SC with Zenithium. This is a durable, lightweight metal alloy that consists of aluminum, niobium, and titanium. Zenith utilized Zenithium on the El Primero 4000SC to bolster the caliber’s shock resistance, as well as strengthen its balance and chronograph bridge.

While the incorporation of Zenithium is an excellent advancement, the contemporary Zenith El Primero 4000SC really does not stray too far from the qualities of the original El Primero 400. This just goes to show that Zenith truly knows how to make an automatic chronograph caliber that barely needs any improvement, even after decades.

Brief History of the Zenith El Primero Movement

While it is one of the most celebrated watch calibers, the El Primero actually had a rather bumpy and underwhelming start. In 1969, Zenith unveiled the El Primero as the world’s first high frequency, fully integrated automatic chronograph movement. Additionally, it was only 6.5mm thick. While the Zenith El Primero was not the thinnest caliber ever, it was definitely impressively slender.

With such specifications and technical prowess, you would have expected the Zenith El Primero’s launch to make the headlines of the watchmaking industry. Unfortunately, it was nowhere near that. During the El Primero’s release, only a handful of local and regional journalists were able to attend Zenith’s press conference.

The bad luck did not stop there. A year after the El Primero’s release, the dreaded quartz crisis took the Swiss watchmaking industry by storm. Since they were more accurate and much cheaper to produce and sell than mechanical watches, quartz-operated watches quickly became all the rage. Ultimately, the ensuing fall of mechanical watches meant that the Zenith El Primero was more neglected than ever.

In 1971, the Zenith brand was sold to the Zenith Radio Corporation, a Chicago-based conglomerate that originally manufactured radios and televisions. Between 1969 to 1975, Zenith produced a total of 32,000 El Primero movements – both the model and the movement. However, in 1975, the new owners of Zenith decided to focus on making quartz watches. 

As part of the brand’s new business direction, the owners ordered all previous Zenith blueprints, presses, and tools to be scrapped or sold. At first, this seemed like the end of the Zenith El Primero movement. However, Zenith watchmaker and chronograph specialist Charles Vermot, along with his brother and another Zenith employee, was able to secretly hide 150 presses, along with some blueprints, tools, and cams, including those of the Zenith El Primero. Zenith’s attempt to join in the quartz watch craze was largely unsuccessful, and the brand had little to no profit during that time. In 1978, Zenith Radio Corporation sold Zenith Watches SA.

In the 1980s, mechanical watches began to undergo a resurgence. This improved situation opened an avenue for Zenith to bounce back and recover from the decade of quartz. After a few years, the brand was able to produce the Zenith El Primero movement once more.

The unexpected return of the El Primero caliber was significant, as it was quickly implemented into the famous sports chronograph, the Rolex Daytona. Rolex’s use of the Zenith El Primero was a strong vote of confidence. Soon after, Zenith also started equipping the El Primero in their own watch models. Wearers were able to witness the Zenith El Primero in action for the first time through the Zenith Chronomaster see-through sapphire caseback.

Today, the Zenith El Primero stands as one of the most popular movements in the industry. Now available in several variations from its base form to versions with flyback hands and tourbillons, this Swiss caliber can be found in numerous Zenith models as well as watches from renowned brands such as Hublot, Bulgari, Tag Heuer, and Panerai.

At the Baselworld 2019, the original Zenith El Primero 400 was given a modern revival. The difference was that this time, it was in front of a great audience with all the media coverage a watchmaker could want. Truly, this is the breakthrough that the El Primero caliber rightfully deserves. After decades of passion and dedication, the Zenith El Primero has risen through the ranks and has become a hallmark of exceptional watchmaking.

10 Watches with the Zenith El Primero Movement

Various models in the market utilize the Zenith El Primero. While this caliber can typically be found in a slew of Zenith watches, there are few models from other brands that also use the coveted El Primero movement. Listing down every timepiece with the Zenith movement would be quite a chore. So instead, we will be narrowing down this list to the top 10 best watches equipped with the iconic Zenith El Primero movement.

1. Zenith Chronomaster Revival El Primero A384 (03.A384.400/21.C815)

There is no better watch to start this list with than the Zenith Chronomaster Revival El Primero A384. This 50th Anniversary special edition watch is a contemporary version of the first Zenith watch to ever be equipped with the El Primero movement. It is the recreation of a timeless classic, updated with modern innovations.

Housed in a tonneau-shaped stainless steel case, the Zenith Chronomaster Revival El Primero A384 features 50m of water resistance and a gorgeous panda dial recreated from the blueprints of the original El Primero A384. It comes with three black chronograph sub-dials, luminous silver hands and hour indices, and a bezel in black that is also marked with a tachymetric scale. Operating underneath the watch face is the one and only Zenith El Primero 400 caliber, complete with its 36,000 vph frequency and 50-hour power reserve.

This Zenith El Primero Anniversary timepiece is worth $6,469 USD.

2. Zenith Chronomaster Revival Shadow (97.T384.4061/21.C822)

A recreation of a Zenith chronograph prototype that dates back to the 1970s, the Zenith Chronomaster Revival Shadow is a handsome watch that blends both vintage elements and contemporary design. Made of high-quality micro-blasted titanium, its matte-finished case is as durable as it is lightweight. Its black dial showcases applied silver indices and hands, along with grey subdials for the 12-hour, 30-minute, and small seconds chronograph functions.

Below the dial of the Zenith Chronomaster Revival Shadow is an El Primero movement that wearers can view through the watch’s see-through sapphire caseback. To finish off the watch’s suave the look, Zenith pairs the Chronomaster Revival Shadow with a black cordura effect rubber strap.

This watch sells for approximately $6,599 USD.

3. Zenith Pilot Type 20 Chronograph Rescue (03.2434.4069/20.I010)

If you are looking for a military-inspired Zenith pilot watch unparalleled reliability, check out the Zenith Pilot Type 20 Chronograph Rescue. Accompanied by a calfskin leather strap in black, this timepiece features a 45mm polished stainless steel case topped with a layer of anti-reflective sapphire glass.

The dial of this Zenith Pilot watch boasts a black sunray dial with vibrant yellow accents from its small second markers, seconds hand, and Pilot signature. The dial’s hour numerals are bold and pronounced and are coated in Super-LumiNova to provide improved legibility in the dark. Running the timepiece is a Zenith El Primero 4069 movement, with 254 components, a 5Hz beat frequency, and a 50-hour power supply. 

This Zenith Pilot piece costs around $5,619 USD.

4. Hublot Spirit of Big Bang Titanium (601.NX.7170.LR)

Hublot is a brand that many enthusiasts and collectors associate with bold and unique-looking watches. Now, with this Spirit of Big Bang Titanium Ref. 601.NX.7170.LR, wearers can enjoy a luxury timepiece with the looks of a sophisticated Hublot and the reliable performance of a Zenith.

This Hublot Spirit of Big Bang watch comes in a sleek, polished tonneau-shaped titanium case that holds and protects the Zenith El Primero-based HUB4700 automatic movement. Its complex skeletonized dial gives the timepiece a distinct appeal while also providing a great view of the caliber at work. For those who want to see this Zenith-Hublot movement from another point of view, you can turn the wristwatch over and look at it through its exhibition-style sapphire caseback.

This Hublot watch is worth approximately $17,269 USD.

5. Zenith Chronomaster El Primero Open (03.2040.4061/69.C496)

Another model from the Chronomaster series, the Zenith Chronomaster El Primero Open is a distinct and stylish watch that displays an open-heart silver sunburst dial. Aside from the aperture that allows you to view the emblematic Zenith El Primero movement, this watch’s dial also has sub-dials bearing the signature tri-colors that the line is known for.

This watch comes in a 42mm stainless steel case equipped with a layer of sapphire glass to protect the dial and an exhibition-style sapphire caseback. You will not have to worry about this timepiece getting wet either as it is water-resistant up to depths of 100m. The watch also comes with a black semi-gloss alligator leather strap.

You can purchase this Zenith piece for around $6,439 USD.

6. Zenith Defy Extreme (95.9100.9004/01.I001)

With an additional escapement that runs its seconds chronograph function at a whopping 50Hz, the Zenith Defy Extreme is a sleek watch that can measure time up to 1/100th of a second. Its case is made out of robust, lightweight titanium, making the timepiece both durable and comfortable to wear. Its beveled surfaces feature a mix of polished and satin-brushed finishes that go very well with the Zenith Defy Extreme’s transparent titanium dial and titanium bracelet. Below the dial is a Zenith El Primero 9004 caliber, which is fitted with 53 jewels and has an impressive depth rating of 200m.

This watch fetches an approximate price of $17,499 USD.

7. Zenith Chronomaster El Primero A385 (03.A384.400/385.C855)

A vintage-inspired design that is also inspired by the Zenith El Primero A384, this Zenith Chronomaster El Primero A385 features a very different colorway. Its tonneau-shaped stainless steel case is paired with a rustic gradient brown dial that darkens towards the rim. Adorned with applied hands and hour indices, the watch face has submerged chronograph sub-dials in white and a white date window that contrasts nicely against the warm hues of the brown backdrop.

Running this watch is none other than the wondrous Zenith El Primero caliber. Wearers who want to see this movement, along with its customized Zenith rotor, can view it through the see-through sapphire caseback. The El Primero A385 comes in a slender 37mm case coupled with a light brown calfskin leather strap.

This timepiece will cost you around $6,679 USD.

8. Hublot Spirit of Big Bang White Ceramic (601.HX.0173.LR)

Whether you are a fan of Hublot or not, this is a striking watch that is bound to get the attention of everyone looking at it. The Hublot Spirit of Big Bang White Ceramic uses a 44m white ceramic case covered by a layer of sapphire glass. This fashionable yet durable composition ensures that the timepiece looks distinct and is highly scratch-resistant throughout its structure.

The dial of this Hublot watch is skeletonized, allowing you to see the El Primero-based HUB4700 caliber in all its glory. Above the movement are luminous hour indices and sword-shaped hands, chronograph subdials of varying sizes, and a date display at the 4:30 position. Paired with a white alligator leather strap, the Hublot White Ceramic is both a reliable timekeeper and a bold fashion statement.

You can get your hands on this particular Hublot piece for $21,649 USD.

9. Zenith Defy El Primero (95.9005.9004/01.R582)

Encased in a 44mm tonneau-shaped titanium case, the Zenith Defy El Primero is a robust and rugged timepiece that provides its with wearers style, convenience, and elegance. The Zenith Defy El Primero showcases a fixed black ceramic bezel and a polished silver dial with black chronograph subdials and luminous hands and hour markers. Layers of anti-reflective sapphire glass protect the front and rear case of the watch while also offering a clear view of the watch face and its El Primero movement. Zenith pairs the Defy El Primero with an alligator leather-patterned black rubber strap.

This Zenith watch retails at around $8,000 USD

10. Zenith Chronomaster El Primero Sport (03.2280.400/01.C713)

The Zenith Chronomaster El Primero Sport is a highly-capable wristwatch that merges sporty looks with classy aesthetics. Its silver-tone stainless steel case stands out beautifully when matched with the watch’s dark brown alligator leather strap. The matching polished silver dial contains applied indices and hands and a date window at 6 o’clock, along with chronograph sub-dials that blend in perfectly with the silver backdrop. A touch of color is added to the timepiece with its bold red seconds hand. This watch is powered by the Zenith El Primero 400B, which differs from the original El Primero 400 in terms of the positioning of its date window.

The El Primero Sport is worth approximately $7,599 USD.

Importance of Beat Frequency in Telling Time

The frequency of a watch is measured using two different terms: Hertz (Hz) and Vibrations per Hour (VpH). Hertz typically refers to the number of oscillations or “swings” the movement’s balance wheel makes in a single second. Each time the balance wheel does half a swing or completes half an oscillation, it is considered a vibration. As such, two vibrations can occur per oscillation. For example, if a Seiko Caliber 6R64 produces 4Hz, which is four oscillations per second, that would amount to eight vibrations a second. In an hour, 4Hz will amount to a total of 28,800 vibrations per hour.

Now, why would knowing this be important? The role of beat frequency when telling time lies in the caliber’s ability to generate oscillations. The higher the rate, the more accurate time-telling will be. Most mechanical wristwatches nowadays possess a beat frequency between 18,000 vibrations per hour (2.5Hz) to 28,800 vibrations per hour (4Hz).

While those numbers are considered quite reliable, a lot of work still needs to be done for mechanical calibers to match the accuracy of quartz movements. The reason why quartz movements are so immensely accurate is that quartz crystals vibrate at an astronomical rate of 32,768 Hertz. Even the most capable high-beat Zenith mechanical watch can only generate 18 Hertz (129,600 vibrations per hour).

Increased beat frequencies are an interest amongst watch collectors because it determines how precise their watches are. With regards to the Zenith El Primero, its 36,000 vibrations per hour (5Hz) allow it to measure time more accurately, all the way down to 1/10th of a second. However, the rate at which a movement beats also affects its power supply. That is why mechanical watches with lower beat frequencies tend to last longer than those that produce higher. It is certainly incredible that Zenith was able to create a large number of models that operate at 5Hz, while also having ample power supplies of around 50 hours.

Final Thoughts

To this day, the Zenith El Primero stands as one of the most coveted and recognizable automatic movements ever created. With its impressive beat frequency, lengthy power reserve, and unyielding reliability, the El Primero continues to amaze watch enthusiasts everywhere.

The Zenith El Primero has made a home in many brilliant models. However, the ten timepieces mentioned above have proven to be some of the best El Primero watches that any brand has to offer. Though there really is no such thing as a bad El Primero watch, make sure to do your own bit of research so that you can land a high-quality and high-performance timepiece that perfectly suits your tastes.

Featured Image By: Zenith Watches

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