How to Set the Torque for a Preset Torque Screwdriver

A threaded fastener used for any assembly process requires proper torque control. Without it manufacturing engineers will end up dealing with the unnecessary issues to resolve product failures. Investigating fastening failures in the manufacturing process is costly and time-consuming.

Mountz preset screwdrivers use the trusted cam-over technology that eliminates torque failures and are designed and manufactured to meet or exceed the accuracy and repeatability requirements of the ISO standard. These screwdrivers are typically used for assembly applications where a single torque setting is required. The tool prevents an inadvertent adjustment of the torque setting by an assembly operator.

A preset torque screwdriver does not feature an external adjustment scale. These tools have an internal torque adjustment mechanism that must be preset using a torque analyzer. When purchasing a preset screwdriver, there are two options for setting the torque. For a minimal fee, the Mountz calibration lab will preset the tool at the requested torque setting. The screw is delivered with an ISO 17025 certificate and calibration label. The other option is to preset the torque value for the screwdriver yourself. The video below will demonstrate and provide a general guideline to perform this process.

For the torque measuring process you will need a torque testing system, a hex key and optional adapters may be needed as well. Always select a torque analyzer or sensor that covers the torque range of the screwdriver.

Adjusting the Torque Setting for a Preset Torque Screwdriver

• Connect the screwdriver to the testing instrument and use appropriate adapters if needed.
• Check the current setting of the screwdriver. Apply torque clockwise slowly until the screwdriver slips over.
• To adjust torque setting remove the end cap.
• To increase the torque setting, loosen the lock screw. Insert the hex key into the internal adjuster and turn clockwise.
• To decrease the setting, rotate counterclockwise below your desired setting. Then turn clockwise to increase torque to the desired value.
• Do not adjust settings above or below the recommended torque range of a tool.
• Check the screwdriver and continue adjusting until the desired torque is reached.
• Once the setting seems consistent, then record the final torque readings.
• Apply calibration label and seal.

To maintain consistent accuracy the preset torque screwdriver must be checked periodically. Overtime a tool starts to drift out of tolerance and needs to be calibrated. A suitable calibration frequency depends on usage, application, risk tolerance, performance history and other factors. To minimize any production downtime, a good preventative maintenance plan should include having backup tools on-site.

Using a quality torque screwdriver and torque testing equipment makes a safer world through accuracy and precision. Controlling torque is essential for companies to ensure their product’s quality, safety and reliability isn’t compromised. The failure of a three-cent fastener that isn’t properly tightened can lead to catastrophic or latent failures. Fasteners that are insufficiently fastened can vibrate loose and excessive torque can strip threaded fasteners.