1. Layer forging

At the beginning, three steel plates are prepared – with alternating layers
high-carbon (harder, sharper) and
low-carbon (tougher, more durable).

2. Welding and forging

The assembly is heated to 1 200–1 300 °C, then welded and forged with a press or hammer
into a single homogeneous block.

3. Folding the layers

The block is cut, folded again, reheated, and forged back together. This process creates multiple layers:

• after the 1st folding: 6 layers
• after the 2nd folding: 12 layers
• after the 3rd folding: 24 layers
• after the 4th folding: 48 layers

If it is necessary to achieve 67 layers, the blacksmith adds additional steel plates at a certain stage and continues folding.
v překládání.

4. Shaping the blade

The finished multilayer block (billet) is reheated, forged into a flat bar, and
then forged or cut into the shape of a knife – either by hand using a template or by machine.

5. Hardening and tempering

The blade is heated to approximately 800 °C and rapidly cooled in a special oil bath (hardening – to increase hardness).
(hardening – to increase hardness).

It is then heated to 150–600 °C (tempering – to reduce brittleness and increase flexibility.).

6. Etching the pattern

The blade surface is etched with acid, which highlights the contrasting layers. A characteristic
wavy or vein-like pattern appears.

Why do we alternate different types of steel?

• High-carbon steel – darker pattern, higher hardness, longer-lasting sharpness
• Low-carbon steel – lighter pattern, greater toughness

The combination creates not only aesthetic beauty but also the ideal balance of hardness and flexibility.

Steel structure after hardening

After rapid cooling, martensite is formed – a very hard but brittle phase with
a tetragonal crystal lattice.
During tempering, the martensite partially transforms and becomes less brittle.
Another present phase is austenite, which provides flexibility.

Summary of the production process

1. Layer composition and welding
2. Repeated folding and forging
3. Creation of a multilayer block (billet)
4. Forging the knife shape
5. Hardening and tempering
6. Grinding
7. Etching to highlight the pattern
8. Handle fitting