A torque screwdriver applies precise rotational force to fasteners. It is available in manual, pneumatic, and electric versions, and has a pressure-sensitive clutch to control torque. Consistent torque improves structural integrity and stability. Regular calibration is necessary for accurate results.
A torque screwdriver is a tool used to turn screw head fasteners into precise, even tension. Torque is the measure of the rotational force applied to twist an object. The English system measures torque in units of foot pounds or inch pounds, and the metric system uses Newton meters. Manual, pneumatic, and electric versions of the torque screwdriver are available to meet the needs of nearly any size project. Most torque screwdrivers are adjustable within a range of torque forces to suit multiple applications.
Manual torque screwdrivers generally have an in-line drive shaft and handle similar to traditional screwdrivers. Electric models can have this same shape or have an offset handle that makes them look more like a power drill. An air or pneumatic torque wrench almost always looks like a drill and is typically the more powerful variety of torque screwdriver.
The unique operating feature of a torque screwdriver is the pressure sensitive clutch. This built-in limiter controls the maximum amount of rotational power applied to the screw by disengaging the drive linkage at the pre-set torque level. Adjusting the position of the clutch allows the user to set the torque within the range offered by the tool. Most manual and pneumatic torque screwdrivers feature a slip clutch and cam-over design that allows the tool to continue running as the drive gears separate. The auto shut-off clutches take it a step further by completely shutting down the electronic torque wrench to allow for even more precise torque control.
Corporate manufacturing operations often use torque screwdrivers to secure multiple joints on a product with equal pressure. Torque screwdrivers greatly reduce the variations between screw fixing attachments that are common when multiple builders are completing a large project together. Equally driven screws increase the structural integrity and overall stability of an assembled member. Over-tightening a screw often splits the material or damages the screw threads and ultimately weakens the connection of the fasteners. Sending the screw too short may not drive it into the second surface and make the connection.
Torque screwdrivers that are used regularly are often tested and recalibrated to ensure consistent torque. A machine called a torque tester is attached to the tool head to provide a reading of the applied rotational power once the torque screwdriver is fully engaged. Damage from extended use can cause bends and cracks in the gears of a torque screwdriver making it unable to sustain a set torque value.
Protect your devices with Threat Protection by NordVPN
