Pure Shear Stress
A pure shear stress in a section is the average stress induced by a force transverse to the section. It is averaged over the total area of the section and is calculated using the classical shear stress equation (S = F/A). An example of a pure shear stress is the average shear stress in the threads of a threaded coupling.
Source: API SPEC 16R, Specification for Marine Drilling Riser Couplings, Exploration and Production Department, First Edition, January 1997. Global Standards