"Tool steel" refers to a family of steel grades that are particularly well-suited to be made into - well, tools. Their suitability comes from their distinctive hardness, resistance to abrasion and deformation, and their ability to hold a cutting edge at elevated temperatures. Tool steels are used for cutting, pressing, extruding, and coining of metals and other materials.

This knife by Damask Co. is crafted with the most popular grade of tool steel, D2. It's strong but not too heavy, and not too hard or too soft. Meaning the knife is easy to carry with you and will last a long time, and is also up to just about any task.