a smooth , oblique - angled endface fracture of an optical fiber 39 useful in low reflectance , low insertion loss mechanical splices is achieved by creating tensile stress in the fiber and scoring the fiber at an angle to its longitudinal axis . tension may be applied by bending the fiber with a flexible platen 16 to which it is affixed , and the scoring may be accomplished by scribing the fiber surface with a sharp point or impressing a notch into the fiber with a blade 28 .