HAP40 Knife Steel
The great advantage of HAP40 knife steel is that it combines the best of the worlds of high carbon (corrosion prone) and low carbon (corrosion resistant) steels. Blades made of HAP40 steel can be ground extremely sharp due to the steel's high degree of hardness, retain their sharpness for a very long time, and are as easy to maintain as a stainless knife.
The HAP40 steel grade has not been used for very long and is therefore still relatively rarely used by Japanese knifemakers for Japanese chef's knives. The reason for this is by no means the performance of this knife steel, but rather the processing procedures that must be mastered in order to forge this material into a perfect blade. Whether santoku knives, gyuto knives or nakiri knives, HAP40 blade steel is suitable for all types of Japanese knives. Traditional knife forges have often existed for many generations and often specialize in the processing of individual types of steel. These traditional companies must become familiar with the specific properties of HAP40 steel before series of knives can be made from this material. However, due to the quality of this steel, we are convinced that more and more forges will produce blades from HAP40 steel.