Man Hours Saved Through Digital Torque And Angle Wrench

The checks are carried out three times per shift and are performed using just one 75Nm ProWrench Opta digital torque wrench. The car manufacturer’s previous method involved using various sizes of dial wrench and the readings were recorded on paper, which was filed at the end of every month. This resulted in an ever increasing archive of recorded data and the potential for misfiled or unclear recorded information.

Crane Electronics’ solution using ProWrench Optas and OptaComms software was selected after careful assessment of the car manufacturer’s lineside torque testing requirements and with the close involvement of the company’s quality control and calibration departments. The tools were rigorously tested together including stringent tests of measurement accuracy. The new method of checking was trialled alongside the existing system before implementation.

Using the ProWrench Opta, the operative takes the wrench to the production line once it has been stored with all the data to carry out a specific check of torque values for a particular group of fastenings. The wrench displays how many bolts have to checked and what the torque targets are. As the minimum and maximum torque values are held within the wrench, it will then inform the operator via tri-colour LEDS if the readings are low, high or exact. In contrast to a paper based system, operators cannot manipulate data and a true picture of the manufacturing quality is given.

All readings taken are stored with time, date, user and VIN (Vehicle Identification Number). At the end of the shift, results are uploaded to Crane’s OptaComms software and then exported to a spreadsheet of recorded data.

Twelve months into the project, the results have been dramatic. There has been a 50%+ saving in operator time to carry out torque checks and there has been a major reduction in production line stops due to torque checks. The ProWrench Optas record all VIN numbers with corresponding torque readings for each model variant, giving excellent traceability. The virtually paperless system, with electronic archiving, is resulting in reduced administration, together with further cost and time savings. The production line now also has increased daily capacity as a result of faster torque management procedures.