Flame Blue Steel: The Beauty of Craftsmanship in Classical Watches
Flame blue is a classical technique in traditional watchmaking of handling steel hands and screws.
As early as the 16th century, craftsmen employ the technique heating the steel watch hands and screws to form an oxidized protective layer. This thin layer of oxidation provides the steel surface with a certain degree of corrosion resistance. As an added benefit, when the hands and screws reach a certain temperature, they become tempered, i.e. less brittle and more ductile, while giving a marvelous deep cerulean blue. This, is flame blue.
Capture the Ephemeral
This particular blue is so captivating due to the special science behind the color. For ordinary objects, they show color because, like ink, they contain tiny colored particles called pigment, which reflects light of that particular color. Therefore, the color reflected is solid and opaque. In contrast, the oxidation layer which gives it the color blue is actually colorless. It creates color through a physical phenomenon known as “iridescence”, which is also why peacocks look so colorful.
If you have a chance to witness how a silver steel hand is heated to flame blue, you will first see it change from gold to brown and then purple before it settles to flame blue. If it is heated further, the steel hand turns light blue and eventually light gray. The entire process takes only a dozen of seconds, while the most mesmerizing shade of flame blue flashes by in a split second. Even heating it a second more or less would mean an entirely different color. This is iridescence in action: heating creates a very thin layer of oxidation on the surface of steel, and this colorless layer changes the angle of light reflected, which then interferes with the light reflected from the steel surface to produce colors. Thus a change in the thickness of the oxidized layer changes also the angle of reflection, thus changing the color it finally produces. So, as heating continues, the oxidation layer accumulates and gradually thickens, varying the angle of reflection, and you can see the changing color.
Flame Blue Steel Nowadays
Modern technology offers far more effective methods for corrosion resistance than were available in the 16th century. Yet, the traditional art of flame-bluing steel remains a symbol of true craftsmanship. Achieving the perfect shade of blue requires expert precision, a keen eye for subtle color shifts, and careful control of temperature—making it an intricate and costly process reserved for skilled artisans.
Today, most watchmakers rely on electroplating or spray-painting to replicate the blue hue, while only a few high-end brands continue to carry out authentic manual flame-bluing. This technique has become a hallmark of luxury and individuality.
At EONIQ Atelier, the Malbec series proudly continues this tradition. Every set of hands and movement screws is individually flame-blued by our in-house watchmakers, then the watch is hand-assembled, regulated, and quality-checked by a watchmaker instead of a supply line. Complemented by a white dial and exhibition case back, the Malbec showcases the vivid contrast and beauty of flame-blued components—a tribute to timeless watchmaking artistry.