A heater manufacturing company was experiencing improper torque control, which was costing them money in rework time and product being damaged by the assembly tools that they were using on the production floor. The heater manufacturer assembles floorboard heaters and in-wall bathroom heaters for residential construction. A deformation with the coated sheet metal used to house the heating element in the floorboard unit occurred during the fastening process.
The production manager started a root cause analysis program to eliminate this costly production problem. They started to test the process and determine what was causing the issue. Using a torque analyzer system they did some destructive testing. They wanted to first determine “at what torque value” that was applied during the fastening process would cause the deformation in the product’s coated sheet metal.
Once the proper torque value was determined for the product, they next examined the pneumatic tools being used in the assembly process. The pneumatic torque screwdrivers were set once every six months or at the time of purchase at a preset torque value. This torque value, however, was derived from a chart supplied by the fastener manufacturer, which was at 80% of the fastener yield value. The torque value did not account for the material the fastener was clamping together, which was causing product deformation, paint chipping, increased rework, and decreased their productivity.
After adjusting preset torque value for the pneumatic screwdrivers, the production manager implemented the EZ-TorQ bench-top torque tester to check the pneumatic screwdrivers periodically. By checking the pneumatic tools more frequently with the EZ-TorQ torque tester, the production manager was able to monitor when the pneumatic screwdrivers would start to fall out tolerance and need to be pulled from the production floor to be recalibrated.
Torque testing equipment is not only designed to operate in a separate calibration room. Using a torque tester as a production line checker is another quality control process that manufacturers should implement into their production process. Checking torque tools with a simple torque tester on the production floor daily or weekly ensures assembly tools aren’t falling out of calibration, which will increase productivity and decrease product defects or rework costs. Validating the proper torque setting for the pneumatic screwdrivers with a torque testing system and implementing a torque tester on the production floor resolved the quality control issues that heater manufacturer experienced during its manufacturing process. The production manager saw the first pass rating of finished products increase a lot. The changes in their processes decreased product defects and rework and increased productivity.
Using a quality torque tester 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.
