| abstract |
A carbon fiber bundle, wherein an average single-fiber fineness is from 1.0 to 2.4 dtex and a roundness is from 0.7 to 0.9 in a shape of a cross-section perpendicular to a fiber axis of a single fiber; the roundness being determined with equation (1): roundness=4πS/L 2 , where S is a cross-sectional area of the single fiber and L is a circumferential length of the single fiber, and S and L are obtained by observing, under an SEM, the cross-section of the single fiber perpendicular to the fiber axis of the single fiber and analyzing the obtained image. |