PURPOSE: A surface treatment part which can prevent bending or fracturing by offsetting external impact is provided to improve the work efficiency of a blasting device by maximizing the replacing cycle of the surface treatment part. CONSTITUTION: A surface treatment part is installed between fixed axes(4) of a blasting machine. The fixed axes pass through a fixed block(3) of the blasting machine. A surface process part performs the roughing work on the surface of a steel sheet and steel pipe using the rotation of a rotary shaft(1). The surface process part comprises a straight pin and a ring. The ring is guided to the fixed axis. The straight pin is integrally formed from the ring.
