Wet end portion seal member for ball screw, and ball screw employing said seal member

A ball screw in which a nut and a male-threaded shaft provided with an arcuate continuous groove threadedly engage by way of a multiplicity of steel spheres inserted between the male threads and female threads, the end portion seal member is capable of being attached toward a front or toward a back from said nut, and has a support frame body arranged at an outside circumference of said male-threaded shaft; a base fabric portion, a back surface of which is secured to an inside circumferential surface of said support frame body; and the cut pile that protrudes in such fashion as to be directed toward said groove from a front surface of said base fabric portion; wherein fiber tip portions of said cut pile are bent and made to abut said groove so as to occlude a gap between said groove and said support body, and good lubricant is retained.