Manganese steel, also known as Hadfield steel or mangalloy, is a type of alloy steel that contains a significant amount of manganese. While manganese steel has excellent toughness and wear resistance, it is not commonly used for traditional swordmaking, including katana.

Manganese steel is primarily used in applications that require high impact resistance and the ability to withstand heavy wear, such as in construction machinery, mining equipment, and railway tracks. Its unique properties make it highly suitable for these industrial applications, but they do not align with the specific requirements of swords.

In swordmaking, the focus is on balancing factors such as hardness, flexibility, and edge retention. Traditional sword steels, like high-carbon steel, are chosen for their ability to be sharpened to a fine edge while maintaining durability and resilience. These steels are optimized for cutting ability, blade performance, and the ability to withstand repeated stress and impact.

While manganese steel may possess certain desirable properties, such as toughness and wear resistance, it is not typically used for swords due to its different metallurgical characteristics and suitability for industrial applications rather than blade-making.

It's important to consult with an experienced swordsmith or expert in the field of swordmaking to determine the appropriate steel type and composition for creating a functional and high-quality sword. They can provide guidance based on their knowledge, experience, and understanding of the specific requirements and characteristics of sword steels.