Abstract: A safety start switch for a pneumatic tool including a main body, a compression strip, a push knob, a coupling element, a spring, and a pivot pin. After a corresponding arrangement of the above-mentioned components, the compression strip is not compressible in the ordinary state since the coupling element rests on the blocking portion of the main body. Meanwhile, the compression strip is downwardly swiveled to move the piston in the same direction responsive to the removal of the coupling element from the blocking position of the coupling element when the push knob is shifted against the resilience of the spring.

Abstract: A pneumatic wrench having a main body, a cylinder, an arresting device, a bearing, an air control hood and an adjusting knob, whereby the air control hood is screwed to a rear side of the cylinder receptacle of the main body, thereby fixing the cylinder, the arresting device and the bearing in place and sealing the cylinder receptacle of the main body, and the air control hood further includes an air intake channel and two corresponding air guide channels that work in cooperation with the adjusting knob having air control channels for controlling the path of and the rate of the air flow in admission into or exhaust out of the cylinder, thereby ensuring an effective control of the rotational direction and torque of an action end of the main body.