Clay Tempered Katana

Clay tempered blade

Clay Tempered Katana

Clay tempered Katana or accurately called differential hardened Katana – Clay tempering is a process of utilizing clay to insulate portions of the metal that should be softened; once the sword is quenched and heated, this will cool slowly.

Clay will be carefully administered with contrasting thickness to the blade and this will eventually be allowed to dry; it will be heated to an integral temperature then quenched usually in water.

This process allows the sword’s spine to cool down at a much slower pace compared to the cutting edge, creating two different metal structures where one is generally harder compared to the other.

Its compound mix is a secret clay recipe that every bladesmith has, and featured here is a list of key ingredients that are necessary to complete the mixture.

The process of clay tempering is an art, so clay tempered katanas are said to be more durable and resistant.

However, for the actual process to be truly effective when creating a strong and resistant clay tempered sword, the treatment should only be operated by a professional; plus, each type of steel should also be responsive to the various types of clay compositions.

Clay Tempered Katana for Sale

A clay tempered katana is customarily made from a carbon steel blade that is professionally and differentially covered with clay slurry to acquire a specific differential hardness along its blade.

Constant quenching and heating will allow the material to go through a couple of steel phases known to be advanced forms – hard and solid.

The method of heat quenching reveals the structure of the katana Hamon which is the pattern of the hardened edge; it is essential to make this clearly visible through polishing which is a process that comes later.

It is also vital to observe that the method of preparing the clay slurry and steel metal application is quite particular. The smith should have adequate knowledge of what proportions to utilize to be able to obtain certain elements of the weapon such as the katana hamon structure, the tang properties, as well as the blade curve.

One can also order the hardness, shape, as well as the katana hamon, then the smith will select the appropriate combination to achieve the best clay tempered steel.

The sword maker or smith starts by preparing the tamahagane which is a block of material made from several sheets of steel that feature varying carbon tenors.

The tamahagane is also acquired through a smelting process – welding and folding layers of carbon steel; this method allows the removal of impurities from the material, resulting in a cleaner steel block.

Characteristics of a Clay Tempered Katana

Listed below are the different characteristics of a clay tempered katana:


A clay tempered katana exhibits excellent durability that is inherited from high carbon steel; the lack of durability in a 1095 carbon steel or T10 steel is compensated by the process of clay tempering.


The clay tempered katana features a differential hardness and solidity due to the non-uniform dissemination of clay slurry; this provides a forgeable and flexible katana spine, as well as a hard and extremely sharp edge.

Clay tempered katanas usually have an edge with a hardness index of about 62HRC while its spine has a hardness index of about 45HRC.

clay tempered Katana

Steel Material of the Clay Tempered Katana

An adequate type of steel for creating a clay tempered katana is the 1095 carbon steel or T10 Tool steel. The difference is in its clay mixture which is applied to each kind of steel and the swordsmith is the person designated to determine this combination.

Generally, several carbon steel layers that have differing carbon tenors are carefully folded to acquire a material that the smith will use to apply the clay coating process.

Advantage of Clay Tempered Blades

When the process of clay tempering is done thoroughly, it will achieve a blade that is flexible and ductile while simultaneously being supportive and strong; the blade will also have a harder cutting surface which helps keep an edge for a longer period.

This is considered as a hallmark of the katana since it produces a hamon or delineating pattern line along the blade’s length, it also separates the softer area from the harder portion.

Additionally, it is also believed that once a modern sword is not produced utilizing this treatment, a lot of sword manufacturers opt to include a fake one to better sell their weapons in the market.

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clay tempered katana