Forging of a Knife Components
We forge all the metal components included in our Laguiole knives.
Making the blades
Our blades are made of T12 steel, either from XC75 (carbon steel), damascus stainless steel or carbon. Produced exclusively for Forge de Laguiole, T12 steel combines durability, rust resistance and ease of sharpening. Forge de Laguiole’s unique methods of forging, combined with tempering, give the blade a perfect cutting edge. The steel comes from the Isère region of France. The first stage is to cut the “skeleton” of the blades before placing them in the induction oven.
These are then heated until they are cherry red (to 900/1000ºC within 6 seconds in the induction oven). The blades are then forged using a sledgehammer (300-ton pressure). This gives us the first blades with the shape of the back, the cutting edge and the heel.
The blade is then shaped when cold using an awl (the 'lifetime' of a single awl is between 15-20 000 blades), and stamped with the Forge de Laguiole logo.
After that the blade is cut with a guillotine, using molds and a 60-ton press (the waste material is melted down).
Once the blade is cut it is slightly bent, so before tempering it in oil we straighten it to restructure the metal. To achieve this we heat the blades in a basket (200 blades per basket) to more than 1000ºC for an hour, then immediately drop them in oil to cool them down. Once the blades are cold they are then reheated to 200ºC for annealing. The blades are shaped to give them their V-edge angle using a special machine to grind the blade.
Annealing: The metal is heated to a temperature near fusion point then slowly cooled to give the steel a homogenous structure.
Tempering: Here the metal is heated to a high temperature then quickly cooled in oil to give a highly resistant, but more brittle steel.
Hardening: Once the steel is tempered we heat it gently to reduce the brittleness, which is how we choose the resistance of the blade.
If it is heated for too long or too quickly, the surface of the steel tends to swell. This has an adverse effect on the cutting quality of the blade.
To maintain the surface we have to ensure the line at which the status of the metal changes is only crossed slightly, and for a very short length of time. The difficulty comes when this line changes position (height) depending on the content of the steel. This is why we need to achieve temperatures of around 900º-1000ºC.
Making the bolsters and liners
Our bolsters and liners are made of two kinds of steel:
- Stainless steel (forged at high temperature)
- Brass (forged without heating)
The stainless steel bar is heated to 900°-1000°C then forged.
Then the bar is cut off ... and the bolsters cut out
Making the Stainless steel liner and Spring
The liners are cut from stainless steel sheets. The bolsters are then welded onto the liner (the soldering points being on the inside).
The liners are then pierced and polished before being assembled.
The springs are cut without heating.
The end is heated, then flattened with a press. This gives us the flat part of the spring where the bee will be forged.
The bee and the top part of the spring are then sculpted (the decoration on the spring is known as the guillochage).
Just like for the blades the spring is heated to 1000°C, then tempered in oil and followed by hardening.