The ability of metal to hold a load under compressive or tensile stress without failure is:

The ability of metal to hold a load under compressive or tensile stress without failure is referred to as strength. Strength is a fundamental property of materials, particularly metals, and it determines how much load a material can support before yielding or breaking. This property is crucial in HVAC applications, where metal components are often subjected to various forces.

Strength is often categorized into different types, such as tensile strength, which measures the resistance of a material to being pulled apart, and compressive strength, which measures resistance to being compressed. Understanding the strength of materials helps engineers and technicians select the appropriate materials for ductwork, supports, and other structural components that must endure specific loads without failure.

While malleability pertains to a material's ability to deform under compressive stress without cracking or breaking, elasticity refers to the ability of a material to return to its original shape after removing the stress, and hardness indicates how resistant a material is to indentation or penetration. While these properties are important, they do not specifically describe the capacity to support loads under stress, which is precisely defined as strength.