A critical resolved shear stress is required to initiate a slip.

The critical resolved shear stress is the value of resolved shear stress at which yielding begins; it is a property of the material.

Critical resolved shear stress is the component of shear stress, resolved in the direction of slip, necessary to initiate slip in a grain.

Boas' first research project involved the verification of the law of critical resolved shear stress for the onset of plastic deformation using single crystals of cadmium grown from the melt.

The relative values of the critical yield stresses govern the development of fabric.The table below shows critical resolved shear stress(CRSS) values used for each of the three model quartzites.

Since this is a threshold value, it is referred to as critical; and since it is a component of the applied force or stress, it is said to be resolved; that is, the critical resolved shear stress.

As an extension of this work, he showed that plots of shear stress vs. shear strain were independent of crystal orientation and he also studied the influence of temperature on the critical resolved shear stress and the form of the stress-strain curve.