Square threads are primarily used in applications where high power transmission efficiency and high-load capacity are necessary. They are the most efficient thread form owing to thread flanks that are perpendicular to the thread axis. As a result, radial forces on the mating nuts are eliminated and system wear is reduced.

Square threads are useful in cases where side loading is likely to occur, since the perpendicular thread flanks eliminate wedging. In such cases, it is necessary to minimize diametrical clearances between opposing threads or independently support the screw and nut to maintain axial alignment.