Reliable precision for sustained use. - Apneumatika

34 | Screwdrivers, tappers, measuring devices | Air Tools for IndustryAchievable torque accuracyTorque accuracy dependingon screwdriver system andscrewdriving application.The torque that can be achievedfor a screw connection dependson the type of screwdriving application.In order to obtain anequal basis for assessment, allthe data for screwdrivers refers toinflexible or "hard" screw connections(30° angle of rotation) at6.3 bar flow pressure. In the caseof lower pressure or flexible or"soft" screw connections, someof the values that can be achievedare well below the nominal values.The torque dispersion alsoincreases. Due to the wide varietyof possibilities, specifications withabsolute values are not possible.If in doubt, use a trial and errorsystem. The table provides anoverview of the advantages andachievable torque accuracy ofthe individual wrench systems invarious characteristic screwdrivingapplications.Screwdriver systems Shut-off clutch Lockover clutch Impulse mechanismImpact mechanismDirect drive(Standstill screwdriver)Featuresfor high, consistenttorque accuracyfor the commonscrew connectionwith sufficienttorque accuracywith low reactiontorque, but withmoderate torqueaccuracyfor high torques atrestricted toleranceaccuracyfor low torqueaccuracy. Maximumtorque when chokingthe motor tostandstillTorqueTorqueScrewdriving applicationsRevolutionsAngle of rotationup to M max.up to approx.30°up to approx.60°Rating of the torque accuracyvery good satisfactory satisfactory low –depending onrequestedM accuracygood to very good low satisfactory low lowlowRevolutionsTorqueabove 60°good – if shut-offfunction is stillguaranteedlow satisfactory low lowRevolutionsTorquegood – if shut-offfunction is stillguaranteedlow satisfactory low lowRevolutionsTorqueAngle of rotationnotdefinablegood – if shut-offfunction is stillguaranteedlow satisfactory low lowRevolutionsTorquegood – if shut-offfunction is stillguaranteedsatisfactory –if function is stillguaranteedlow low –if screw is still beingturnedlesssuitableRevolutions