Mechanical stress at rupture, under shear loading. Uses units of pressure (force per unit area). Shear strength is an "ultimate" type strength, and is not to be confused with shear yield strength (which is seldom provided in material supplier datasheets).
Shear strength is an important property for the performance of fasteners, which experience primarily shear loading during service. It is also important for laminar composites and wood, where it is measured under different orientations with respect to the layers or grain. Interlaminar shear strength is the shear strength of the interfaces between layers in a laminar material.
ASTM testing standards include B831, D732, D4255, D5379, and D7078. ISO standards include 3597, 12579, and 14130.