Abstract: A torque impulse power tool primarily intended for tightening threaded joints comprises a housing (10), a rotation motor (11), a torque impulse generating mechanism (13), and a reduction gearing (12) coupling the impulse mechanism (13) to the motor (11). A torsion spring (21) is associated with the reduction gearing (12) to reduce substantially the difference in deceleration between the motor (11) and the impulse mechanism (13) by yielding elastically to the driving and inertia forces of the motor (11) and the gearing (12) during each impulse generation. The torsion spring (21) is connected to absorb the reaction torque peaks developed in the gearing (12) or the driving torque peaks between the gearing (12) and the impulse mechanism (13).