pound-force second/sq. foot Unit Converter

Definition of pound-force second/sq. foot unit

Pound-force second per square foot is a unit of dynamic viscosity in the Imperial/U.S. customary system. It represents the shear force, in pound-force, required to maintain a velocity gradient of one reciprocal second across a fluid.

History of pound-force second/sq. foot unit

This unit developed from British and American engineering practice, where the foot, second, and pound-force formed a practical mechanical measurement system. It is the customary-system counterpart of the pascal-second and is closely related to the older unit called the poise. As industrial fluid mechanics matured during the nineteenth and twentieth centuries, engineers used pound-force-second per square foot in lubrication, hydraulics, and aerodynamics. Although SI units later became internationally preferred, the unit remained familiar in aerospace, petroleum, and mechanical-engineering references, especially in countries using English customary specifications.

Applications of pound-force second/sq. foot unit

Today, pound-force second per square foot appears mainly in legacy data, engineering handbooks, and specifications for lubricants, hydraulic fluids, and polymer materials. It is useful when modeling resistance to flow in pipes, bearings, dampers, and aircraft systems. Modern calculations often convert it to pascal-seconds, while specialized software may retain it for compatibility with customary units.

Complete list of pound-force second/sq. foot unit conversion