This specification covers one type of continuous multifilament carbon fibers in the form of a tow or yarn (when twisted). The weight per unit length of the tow or yarn is governed by the filament count which is identified by the supplier's grade or material designation. Carbon tow or yarn, derived from a polyacrylonitrile precursor, with typical 325 ksi (2241 MPa) tensile strength and 57 Msi (393 GPa) tensile modulus for use in general purpose structural composites requiring moderately high tensile strength and high modulus of elasticity in tension