Carbon fiber strand and process for its production

Strand carbon fiber comprising a bundle of 20,000 to 30,000 carbon fibers, each cualestiene on its surface, a plurality of parallel to the direction of fiber axis of the carbon fiber and folds inthe which as measured by microscopy scanning probe, a distance between folds on the surface of carbon dichafibra is 100-119 nm, a depth of crease on the surface is 23 to 30 nm, a mean diameter defibra is 4.5 to 6.5 um, specific surface area is 0.6 to 0.8 m2 / g and a density of grading 1.76g / cm3 or more, wherein said carbon fiber strand has a tensile strength of 5650 MPa or strand Moreand voltage module 300 GPa strand or more; a strand wound with a tension of 9.8 N has unaanchura strand of 5,5 mm or more; and no strand breakage is observed in a method of evaluating deseparacion strand where a voltage of 9.8 N is applied to a carbon fiber strand running.