Know Your Watches: Finishing Techniques In High-End Watchmaking

As someone who writes about watches, it’s very often that I'm met with a barrage of questions. Many are directed at my preferred choice of employment and whether the money I make jiggles or folds. While I feign a pained expression and a slow head shake trying to avoid the same, it inevitably and instantly gets followed up by the one that goes “Why are watches so expensive?" For this one though, I do have an answer and that answer is usually the biggest flex I got. Moreover, there’s a catch, their “expensive” is what we consider entry-level, for the comprehension that a watch can cost as much as a fancy house in an affluent suburb, gives them a check of luxury that is way beyond hitching a ride in the Virgin Galactic. When you work in an industry that thrives on flamboyance, why be humble? Alright, back on earth.

Why watches are really that expensive is more of a combination of a few factors that together make a product evidently sat within the highest echelons of refinement. Among the factors at play, it is usually the decoration or finishing and the effort as well as time spent on the same that establishes a true differentiator, setting apart mere luxury from handcrafted perfection. I remember watching a 10-minute documentary film titled “Time Piece” back in the day. In it, a certain Philippe Dufour remarks, “I always say the value besides the gold or platinum case is what we (watchmakers) add. We spend a lot of hours and days making things nice with nice finishing. In fact, it's what gives the product its value. When you compare it with mass produced, we produce watches with a soul." It resonates with the very emotion of Horacio Pagani, an Italian car-maker who attests with a similar remark, “Everything is machined and then finished by hand, because the artist’s hand gives the added value that the machine, while accurate, cannot give."

While time itself is a core utilitarian dimension, it’s artisanal decorative works achieved through hand-finishing bare metal that give its expression a poetic attribute. After all, there’s a difference in 10:10 on a Seiko 5 and 10:10 on a Rexhepi Chronomètre Contemporain. No need to bother DeepSeek yet, for our Know Your Watches series returns with an exhaustive exploration of watch finishing/decoration techniques. Also, it’s a hint to invest in an eye loupe.

What is finishing anyway and why does it matter?

Watch finishing is a process amalgam of quite a number of techniques employed to ‘beautify’ the many components that make a timekeeper. Between the processes of fabrication and assembly of these components, many treatments, some functional, some decorative, are performed with a primary objective to enhance their finesse. In a poetic sense though, watch finishing, particularly movement finishing, is an attribute by which the haute-ness of an haute horlogerie timepiece can be measured. By elevating a mere metallic component to something that delivers an accomplished ocular delight is actually the benchmark here. There's levels to it and as already established, costs attached. But as I say, art is priceless.

Why bother finishing a watch and its components has a two-fold purpose - functional and decorative. Certain finishing techniques find an application for better mechanical performance and longevity. With parts transferring motion via mechanical engagement, polishing the moving components, like gear and pinion teeth, reduces friction and overall wear and tear while complementing movement efficiency. Certain techniques with a dual purpose are heat-bluing and black polishing which are surface treatments not only employed for aesthetic enhancement but also to make metal components better resistant to corrosion. Then are decorative finishes like anglage or engraving where painstaking works pose as exhibits of a watchmaker’s skill level. With no inherent functional purpose, decorative finishing stands as a true differentiating factor between good and the very best.

In our series, we’ll narrow in on the many finishing techniques specific to watchmaking while slightly stressing on the processes, challenges and benchmark executions of each. Let’s cover it alphabetically then.

Anglage

In the evolutionary tale of traditional watchmaking, many finishing processes were born out of necessity. In order to even out the burrs on a movement part’s edge from a cutting tool, a filing followed by polishing of the edge was sought to yield a uniform surface. This evolved into what we know as anglage or beveling, watchmaking’s parallel to chamfering between the part’s upper surface and the flank. When removing the tool marks on the edge, a 45-degree angle gets created and when polished to a mirror finish, it helps differentiate parts with a sheen along their periphery. Anglage can either be angled or convex curved, but has to be consistent in regards to highly reflective finishing.

The technique of anglage is dominantly applied to right-angled edges of movement bridges and plates. The process starts by filing the edge if the part isn’t pre-angled/chamfered, and then polishing with special wood pegs. One key area of focus in high-end watchmaking is the perfection of ‘inward angles.’ It refers to the point where two beveled edges meet. With tolerances close to less than fractions of a millimeter, curving the metal inwards to produce a fine edge along where the surfaces meet is easier said than done. Impossible to be achieved with any machine, this is where true watchmaking skill is demonstrated and thus very few watches feature movement components with finished inward angles.

While many watch movements feature beveling, the true masters of the technique of anglage, notably its rounded execution, are few. The works of Philippe Dufour, Romain Gauthier and Rexhep Rexhepi are textbook examples of the highest order of anglage achieved through traditional hand-finishing.

Azurage

Creating a rippled effect, azurage is the technique of carving repetitive patterns of finely textured concentric circles. This finishing technique is common in sub-dials, particularly on chronograph watches. The overlapping concentric circles differentiate the sub-dials from the rest of the dial while adding depth to a watch face. Notice in the TAG Heuer Carrera Chronograph and Patek Philippe 5236P pictured below, how the azurage on sub-dials elevates the dial’s details.

Bluing

Heat-bluing is a complex and time-consuming process which is usually performed in conjunction with another laborious finishing technique - polishing. A mirror polished component, preferably steel, is heated to a specific temperature in order to obtain a desirable hue of blue. The bluing process is traditionally applied to watch hands and screws. While there are ‘shortcuts’ to bluing a watch component, the traditional process relies on flame-bluing or heat tempering. Through careful temperature control, any metal component can develop a consistent color shift to attain a blue-ish hue while retaining the lustrous finish beneath. A flame-blued surface resists corrosion better thereby improving the longevity of the component.

As a bonus, you’ll find Roger W. Smith’s tutorial on bluing a set of hands for one of his bespoke Series 2 wristwatches here. He remarks that, “It's all a matter of judgement really to get the right color.” As evident from the video, the process itself is very delicate and actually a hit and miss, with the watchmaker’s skill-level and luck coming into play to have it perfect in one go. While heat blued components crowd the watchmaking scene, there are exceptions. I would say the De Bethune DB28 Kind of Blue is a masterful execution of the flame-bluing treatment. It flourishes in its excesses with nearly every visible component including the 42.6 mm titanium case heat treated to a brilliant blue. This watch is absolutely the end game in bluing.

In the age of mass-produced, where making cheaper and faster is the objective, the emotion of handwork gets somewhat lost in this pursuit of ‘manufactured finesse.’ The very soul of traditional watchmaking is somewhat disappearing and it is only through the blessed hands of a very few, that the craft lives on.

In the next instalment of Know Your Watches series on watch finishing, we’ll cover some more amazing techniques. Till then, enjoy your time with the loupe.