Torque is a force people rarely recognize as they go about their day. There is torque that is applied and torque that is measured. With the Mountz dial torque screwdrivers, measuring torque is simple and ensures a proper production and quality assurance system.
A dial indicating torque screwdriver is designed for torque evaluation and torque verification. It is a low cost versatile tool that can be utilized for torque auditing or R & D torque testing and product evaluation. The Mountz dial indicating torque screwdriver can be used to monitor torque as it increases or decreases or display peak torque applied on a fastening application. Mountz dial screwdrivers measure torque through the use of known twisting force needed to distort a torsion bar. The screwdriver is a dual scale tool marked in metric and imperial units, and meets ISO 6789 accuracy requirements.
The dial screwdriver can be used in track or peak mode and is operational in both directions in either mode. In track mode the torque value applied is constantly tracked and displayed. When the torque is released, the pointer returns to zero. Peak mode tracks the torque, but leaves a memory pointer at the maximum torque position.
Torque Measurement & Verification
The dial screwdriver is used in two common torque verification tests. One is the first movement test and the second is the loosening test.
1) First Movement Test – Once the fastener has been tightened, employ the use of torque measuring tool. Mark the tightened fastener and surrounding application. In the tightening direction, begin to slowly apply force to the tool until the first movement in the fastener is noted. The reading recorded is a good indication of the original torque applied to the joint. This is the best way to determine residual torque.
2) Loosening Test – This is a similar process to the first movement test described above, except instead of the tightening the fastener, the torque is applied in the direction that loosens the fastener. At the point the fastener breaks loose, the torque reading is recorded. The torque value to loosen the fastener is the approximate torque that was applied to the joint.
General Information on Torque Specifications
When determining a torque specification for a new fastening application, 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 measuring instrument on the actual material and fastener to be joined. An evaluation is usually conducted with ten parts, ten fasteners, and a torque measuring tool. 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.
Using a quality dial measuring torque screwdriver 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 torqued can vibrate loose and excessive torque can strip threaded fasteners. t is important for many companies to ensure that proper torque is being applied and maintains gauge requirements associated with the ISO 9001 Quality Standard.
Improve your quality process with a minimal investment. Contact us today to find the proper dial torque screwdriver for your torque measuring needs.