The maximum compressive stress that can be sustained by the test specimen during a compressive test. It is usually only determined on brittle materials.
Ultimate Compressive Strength is defined as the force at which a specimen with a certain cross-section, and consisting of a particular fracturing material, fails when it is subjected to compression. The ultimate compressive strength is normally measured in N/mm2 (force per area) and is thus a stress. It is understood to mean that force that is distributed evenly over the cross-section of a body (component).
Note: The compressive strength of materials that do not break under compressive force must be defined as the compressive stress needed to deform the material by an arbitrary amount.