| Continued
manufacturers are realizing that precise torque control can spell the difference between a safe, reliable, and economical product and complete disaster.
“Anybody who has to tighten a threaded fastener and needs to control, monitor, or measure torque needs sophisticated torque tools," according to Brad Mountz, President/CEO of Mountz Inc. "Likewise, if OEMs want to save money, make their workplace safer, enhance product quality, or reduce
their exposure to liability; only specialized high-quality torque tools will get the job done properly."
The following 10 tips for achieving precision torque control will give OEMs vital information needed to streamline their production processes:
1. Determine Torque Requirements
When determining correct torque specifications, the engineer must consider the maximum load placed on the fastener, the strength of the material joined, and whether the joint is hard or
soft. A hard joint connects materials directly. In this case, the fastener rotates very few degrees to develop full clamping force after it encounters the material. Since a soft joint contains a gasket or involves compressible materials, it requires additional tightening after the fastener makes contact, to achieve full clamping force.
One recognized method is to perform a destructive test with a calibrated torque control tool on One recognized method is to perform a
destructive test with a calibrated torque control tool on the actual material and fastener to be joined. An evaluation is usually conducted with ten parts, ten fasteners, and a calibrated torque control tool with a transducer. First the fastener is tightened to the point of failure, then repeated several times to verify the consistency of the failure point. Now another series of tests is begun whereby the joint is torqued to 75% of the failure point. Depending on how the parts will
be used, the tightening can be reduced by any degree necessary. If parts on a machine are subject to heavy vibration, maybe 85% of the total force is necessary for good torque control.
2. Pick the Right Torque Tool
A wide variety of tools are available to control and measure the torque applied to fasteners, from electric screwdrivers to large industrial wrenches, analyzers, sensors, and multipliers. These tools utilize calibrated torque setting mechanisms
that may be factory pre-set or user-definable. When the specified setting is reached, the tool gives a visual, audible, or tactile signal.
The selection of tools for a given application is determined by the anticipated production output, the type of materials being joined, the amount of torque required and the specified fasteners. Lighter materials such as wood or plastic may require only lightweight tools; likewise, heavy materials such as steel may require stronger or larger
tools. Tools should also have connection ports for an RS-232 PC cable if torque data must be gathered electronically. |
