Every mechanical watch has an escapement. It’s the component that controls how energy from the mainspring is released, and it’s responsible for the ticking sound you hear when you hold a watch to your ear.
For over 250 years, the Swiss lever escapement dominated the industry. It worked well enough that nobody seriously tried to replace it. Then a British watchmaker called George Daniels decided it could be done better.
The result was the co-axial escapement, an invention that Omega adopted in 1999 and has since rolled out across its entire collection. It’s now one of the defining technical features of the brand. But what does it actually do, and should it matter to you as a buyer or collector?
What Does the Escapement Do?
Before getting into what makes the co-axial different, it helps to know what an escapement is doing in the first place.
A mechanical watch stores energy in a coiled mainspring. As that spring unwinds, it drives a series of gears (the gear train) that move the hands around the dial. The escapement sits between the gear train and the balance wheel, acting as a gatekeeper. It releases energy in small, controlled bursts, one tick at a time, so the watch runs at a steady rate and not all at once.
The balance wheel oscillates back and forth, and the escapement gives it a tiny push (called an impulse) with each swing to keep it going. How cleanly that impulse is delivered has a direct effect on accuracy and on how quickly the movement’s lubrication wears out.
The Problem With the Swiss Lever
The Swiss lever escapement has been the industry standard since the late 18th century. It’s proven, reliable and well-suited to mass production. But it has one fundamental weakness: friction.
In a lever escapement, energy is transferred to the balance wheel through a sliding action. The pallet stones (small jewels mounted on the lever) slide against the escape wheel teeth every time they lock and unlock. That sliding contact creates friction, and friction means the surfaces need lubrication to avoid wear.
Over time, those lubricants degrade. They dry out, thicken or migrate away from where they’re needed. When that happens, the watch gradually loses accuracy, and eventually it’ll need a full service to clean and re-oil the movement. This is one of the main reasons manufacturers recommend servicing a mechanical watch every five to ten years.
George Daniels believed he could design an escapement that dramatically reduced this sliding friction, extending the time between services and improving long-term accuracy.
How Is the Co-Axial Different?
The key difference from the Swiss lever is in how energy is delivered to the balance wheel.
In a co-axial escapement, the system uses two escape wheels mounted on the same axis (hence “co-axial”) and three pallet stones instead of two. The locking function, which holds the gear train in check, is separated from the impulse function, which pushes the balance wheel. This separation is critical.
In a Swiss lever, locking and impulse happen on the same surfaces, which is where the sliding friction comes from. In the co-axial design, the impulse is delivered more tangentially, with much less sliding contact. The result is significantly reduced friction at the point where it matters most.
In practical terms, this means the lubricants in a co-axial movement degrade more slowly. The escapement stays accurate for longer, and the intervals between services can be extended. Omega backs this up with a five-year warranty on its current Master Chronometer watches, a reflection of the confidence the brand has in the technology’s long-term reliability.
From Prototype to Production
Daniels spent years trying to convince Swiss manufacturers to adopt his invention. He fitted it into his personal Omega Speedmaster Mark 4.5 in the mid-1970s and built several more prototypes, but the industry showed little interest. The quartz crisis was consuming everyone’s attention, and a new mechanical escapement wasn’t a priority.
It took until the early 1990s for Daniels to find a partner. Nicolas G. Hayek, then chairman of the Swatch Group, recognised the potential and backed the project. Industrialising the co-axial for mass production was a considerable engineering challenge. Daniels had made his components by hand, and translating that into a process that could produce hundreds of thousands of movements per year required years of development.
The first commercial co-axial watch arrived in 1999 in the Omega De Ville, fitted with the Calibre 2500. It was a landmark moment, but the early calibres had teething issues, and it took several generations of refinement before the technology matured into the reliable, proven system it is today.
Where the Co-Axial Sits Now
Today, every current Omega collection uses co-axial movements. The Seamaster, Speedmaster, Constellation and De Ville all run on calibres featuring the co-axial escapement, paired with silicon Si14 balance springs and anti-magnetic components.
Since 2015, Omega has combined the co-axial with its Master Chronometer certification, developed in partnership with the Swiss Federal Institute of Metrology (METAS). This puts each finished watch through eight tests over multiple days, covering accuracy, magnetic resistance to 15,000 gauss, water resistance and power reserve performance.
The accuracy standard for a Master Chronometer is 0 to +5 seconds per day, tighter than the COSC chronometer standard that most Swiss brands use as their benchmark. By 2025, Omega had certified over 2.5 million watches to this standard.
The combination of the co-axial escapement and silicon balance spring technology gives Omega’s movements a genuine technical edge. The silicon spring is anti-magnetic and thermally stable, which complements the co-axial’s reduced friction to produce a movement that stays accurate in real-world conditions, not just on the test bench.
Does It Affect Resale Value?
The co-axial escapement is one of the reasons Omega holds its position so well on the secondary market. It’s a proprietary technology that no other brand uses at scale, and it gives collectors and buyers a concrete technical reason to choose Omega over competitors using conventional lever escapements.
Watches fitted with later-generation co-axial Master Chronometer calibres, like the Calibre 3861 in the current Speedmaster Professional or the Calibre 8900 in the Seamaster Planet Ocean, are broadly well-regarded on the pre-owned market. The technology is proven, parts availability through Omega’s service network is strong, and the METAS certification provides documented proof of performance.
Earlier co-axial calibres, particularly the first-generation Calibre 2500, are viewed with slightly more caution by some buyers due to the known issues with early production runs. That said, most of these have been addressed through service, and a well-maintained Calibre 2500 watch still represents good value. As with any watch, factors like condition, provenance and original documentation will all influence what it fetches on the secondary market.
Why It Matters
The co-axial escapement is the most significant innovation in mechanical watch escapement design since the lever itself. It’s not a marketing exercise. It solves a real engineering problem, reduces friction at the heart of the movement, and it delivers measurable benefits in accuracy and service intervals.For anyone considering an Omega, it’s worth knowing what’s inside. The co-axial is one of the things that makes the brand genuinely different from its competitors, and it’s a feature that adds to the lore of the watch, holds real value, both technically and on the secondary market.
