螺丝a screw螺母a (screw) nut螺帽a (screw) nut螺栓a (screw) bolt螺钉a screw
螺杆，螺丝钉 screw/screw bolt/screw nail螺母 (screw) nut
螺丝screw螺母nut螺帽screw cap螺栓,螺钉bolt
