Ang pambansang pamantayang numero para sa hexagon socket head screws ay GB70-1985. Mayroong maraming mga pagtutukoy at laki, kabilang ang 3 * 8, 3 * 10, 3 * 12, 3 * 16, 3 * 20, 3 * 25, 3 * 30, 3 * 45, 4 * 8, 4 * 10, 4 * 12, 4 * 20, 4 * 4, 4 * 25, 4 * 4, 35, 4 * 45, 5 * 10, 5 * 12, 5 * 16, 5 * 20, 5 * 25, 6 * 12, 6 * 14, 6 * 16, 6 * 25, 8 * 14, 8 * 16, 8 * 20, 8 * 8 , 8 * 20, 8 * * 40, at iba pa.