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 fiber, derived from a pitch precursor, with typical 300 ksi (2068 MPa) tensile strength and 75 Msi (517 GPa) tensile modulus for use in general purpose structural composites requiring very high modulus of elasticity and moderately high tensile strength