Red Seal Tool and Die Maker Practice Exam

The correct choice for the material property primarily responsible for a tool's ability to resist deformation is hardness. Hardness refers to a material's resistance to localized plastic deformation, which means it can withstand wear and indentation without permanently deforming. Tools made of harder materials tend to maintain their shape and cutting edges, which is crucial in applications that involve abrasion or the forces of cutting.

In contrast, strength is a broader term that encompasses a material's ability to withstand an applied load without failure, but it does not specifically address how well a material can resist deformation under localized stress. Ductility describes a material's ability to deform plastically without breaking, which is useful in some applications but does not directly correlate to resistance to deformation under tool-related stresses. Toughness combines strength and ductility and is a measure of how much energy a material can absorb before fracturing; while it is an important property, it does not specifically address deformation resistance like hardness does.