What is the ultimate tensile strength of a material?

The ultimate tensile strength of a material refers specifically to its capacity to withstand loads that are applied in tension, which is a type of longitudinal stress. This measure is critical in engineering and materials science because it quantifies the maximum stress that a material can endure before it fails or breaks under tension. Understanding the ultimate tensile strength allows engineers and designers to choose appropriate materials for various applications, ensuring safety and structural integrity.

While other options mention important material properties, they do not accurately define ultimate tensile strength. For instance, the ability to stretch without breaking describes ductility, not tensile strength, and hardness pertains to a material’s resistance to indentation. Similarly, thermal conductivity measures the ability of a material to conduct heat, which is unrelated to its tensile properties. Thus, option B is focused specifically on the relevant characteristic of tensile strength.