When selecting a material selection for an application, it is important to consider its mechanical properties. These are properties that describe how a material performs under some type of load (or force), such as hardness and toughness. While these are often used interchangeably, they have some key differences.
Hardness is a material’s ability to resist scratches and abrasions. This is important when determining what materials will be wear resistant. Diamonds and ceramics would be considered a hard substance because they are very difficult to scratch.
Toughness is a material’s ability to resist a sudden force or impact without snapping, breaking, or shattering. Softer steels or stainless steels are considered tough, because of its ability to stretch and bend, rather than break.
It is important to achieve a balance between these two properties, in order to increase tool life. If a material is too hard, it will be more susceptible to breaking under impact. On the other hand, if it’s not hard enough it will scratch and wear very quickly. The manufacturing process and the type of steel used can also influence the hardness and toughness of a cutter.