Industry is ruled by standards, overseen by national and international standardizing bodies.
Whether it’s the International Organization for Standardization (ISO), Deutsches Institut für Normung (DIN), American Society of Mechanical Engineers (ASME), American National Standards Institute (ANSI), or American Society for Testing Materials (ASTM),each serves a specific purpose.
ASTM F2482 is the standard that covers “externally threaded … fasteners, capable of indicating clamping forces up to yield strength during the tightening process or post installation residual tension, or both” — in other words, fasteners that indicate tension.
In existence for more than a century, ASTM is the largest organization in the world for developing and publishing voluntary, full-consensus standards. The ASTM process for creating new standards requires collaboration among industry participants to develop and finalize language and standards, then a wider vote to accept it. In 2002, Valley Forge & Bolt, maker of patented bolting products, recognized the importance of having a consensus standard detailing the requirements for load-indicating fasteners and approached a subcommittee of the F16 Committee on Fasteners. After two years, peer collaboration and several ballots, the standard was accepted.
Currently, 17 years after the acceptance of the ASTM F2482 standard, Valley Forge products are still the only ones that comply with the specification that fasteners accurately measure tension as a percentage of load to within +/- 5 percent. Those products are Maxbolt® and SPC4®.
“If the customer is serious about controlled bolting for their critical joints, it will be important to them that the fasteners they use achieve the +/- 5-percent accuracy standard,” said James Brooks, director of engineering. “It is for applications where reliability, safety and certifiable product performance are critically important.”
The ASTM F2482 standard promotes safety by its sheer accuracy at measuring tension from within the critical joint. Because Maxbolt and SPC4 can literally tell maintenance personnel, by percentage of load, how close they are to appropriate tension, those maintenance workers can make timely, better-informed decisions about when to retorque, replace or leave bolts alone. This extends fastener life and helps to prevent machinery and equipment from operating with bolts that are out of tension — the leading cause of bolt failure.
Brooks explained the Valley Forge Maxbolt and SPC4 occupy a valued space in the current ASTM F2482 standard among mechanical and electronic-type fasteners, as competitors generally can only deliver +/- 25-percent accuracy. “At that point, you’re getting roughly the same tension accuracy achieved by using only a torque-based solution, so it makes little sense to invest in tension-measuring fasteners,” Brooks added.
For more information, visit www.vfbolts.com or call (602) 269-5748.
