Lets the user hold the tool with one hand and offers better accessibility in some cases. Pistol grip Enables the user to hold the tool and apply up to 10 N⋅m of torque more than that is not recommended due to ergonomics. The torque ranges typically from 0.02 N⋅m to at least 27 N⋅m, with speeds of up to 2,000 revolutions per minute (rpm).Įlectric screwdrivers with transducers can be categorized into three groups according to their physical features: Brushed electric motors and more efficient brushless motors are used. This type is the one mostly used for industrial assembly applications such as electronic assembly and small parts assembly.

In an industrial environment dedicated tools optimised for their particular function are more often used.Ĭorded electric torque screwdrivers are commonly made in three different designs: pistol grip, angle and inline. Drilling responds to the same description general-purpose power tools ('drill/drivers') are designed for both screwdriving and drilling, with a slipping clutch and low speed added to the drilling functionality. Screwdriving requires torque to be applied by a rotary motion.

Manual torque screwdrivers can have a range of 0.04 N⋅m (6 in oz) to 20 N⋅m (170 in lb). Manual torque screwdrivers are made in straight and pistol-grip models. The torque may be provided manually (by the operator's wrist), by an electric motor, or by a pneumatic drive. They provide precision torque control and reduce energy consumption by eliminating idling.

Auto shutoff tools are designed for critical applications. It will continue to run until the operator releases the throttle.Īn auto-shutoff clutch switches off the tool once the maximum torque is reached. This clutch style is similar to the “cam-over” once the final torque is reached because the clutch continues to cam over and slip. In some cases a tool may need to be certified in a calibration lab to verify its torque output a certificate may be issued by an organisation such as NIST in the United States.Ī Cam-over clutch is usually found in a manual torque screwdriver where the clutch simply “fags“ or “cams-over”, meaning that it signals the maximum torque has been achieved.Ĭushion clutch or “slip clutch” styles are found in both electric screwdrivers and air screwdrivers. Each type has the ability to preset a specified torque value. Most of these clutch types are used in electric screwdrivers, air screwdrivers, impulse screwdrivers, manual torque screwdrivers, and cordless torque screwdrivers. Torque screwdrivers are available with several types of clutch, including “cam-over”, “cushion clutch”, and “auto shutoff”. On simpler tools the clutch settings may be marked with arbitrary numbers (e.g., from 1 for the lowest available torque to 20 for the highest, without necessarily having a linear relationship with actual torque) rather than torque values. The torque limiting clutch is the part of the tool that limits the amount of torque being applied to the fastener at the receiving end of the tool. This is achieved with steel balls rolling between indented plates, compressed by a spring at one end, and the other side driving a screw or fastener. The clutch is the component that defines a torque screwdriver. Torque screwdrivers and torque wrenches have similar purposes and mechanisms. Although no single tool covers the entire range, low-, mid-, and high-torque ranges are available. Torque screwdrivers can exert torques from 0.04 N⋅m to at least 27 N⋅m. All have a torque-limiting clutch that disengages once the preset torque has been reached. Most torque screwdrivers allow the torque to be set to any value within a range. Torque screwdrivers are used in mechanical production, manufacturing, and maintenance their use is part of quality assurance. An insufficiently tightened screw connection may loosen in operation, and excessive tightening can damage parts for example, if the nuts holding the wheel of a car in place are too loose, or damaged by overtightening, a wheel may come off at speed. JSTOR ( May 2012) ( Learn how and when to remove this message)Ī torque screwdriver is a screwdriver with components that ensure tightening to a specified torque, ensuring tightening which is sufficient, but not excessive.Unsourced material may be challenged and removed.įind sources: 'Torque screwdriver' – news Please help improve this article by adding citations to reliable sources. This article needs additional citations for verification.

Electric drill and screwdriver