Torque is a critical component in manufacturing many products. Once the assembly process is completed, measuring torque isn’t finished. A threaded fastener should be audited to verify the joint has been tightened to the proper torque specification. Verification ensures compliance to quality requirements.
Residual torque is the amount of tension that remains in a joint after it has been fastened. The best method to verify a fastener is installed properly and the torque requirement is achieved is to test the residual torque. Auditing is a process used to substantiate consistency and uncovers inaccuracies within the fastening process.
Traditionally there are there three main torque audit methods. The video below will demonstrate the “First Movement” test method using a digital torque tester and torque sensor. This test method can also be accomplished using a dial torque screwdriver, a dial torque wrench or a digital torque wrench.
First Movement Torque Test
Once the threaded fastener is tightened, select a 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.
Even the most sophisticated fastening systems needed to be audited to ensure accuracy and repeatability performance goals are being maintained. Overtime tools start to drift out of tolerance. A method to detect loose fasteners or any signs of joint relaxation can be discovered from a torque auditing program.
Using quality torque measurement equipment makes a safer world through accuracy and precision. Measuring 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.
The objective for auditing is to confirm that the design and manufacturing requirements are being fulfilled. With 50 years of torque experience, Mountz is a pioneer in developing torque testers and torque sensors. Need assistance with conducting a first movement test or measuring torque? Contact us we’re happy to assist.
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