Compressible-washer-type direct tension indicators must meet the requirements of which standard?

Compressible-washer-type direct tension indicators are specifically designed to provide a visual indication of the tensile load in a bolt connection. The requirements for these devices fall under the ASTM (American Society for Testing and Materials) standards. ASTM provides comprehensive guidelines that ensure the performance, quality, and safety of materials and products, including those used in structural applications like bolts and tension indicators.

The ASTM standards relevant to compressible-washer-type direct tension indicators outline the necessary testing procedures, material properties, and performance metrics to ensure that these indicators function effectively and reliably in the field. Adhering to these standards is crucial for ensuring the integrity of bolted connections in structural assemblies, thereby enhancing the overall safety and durability of the structures they are a part of.

In contrast, ISO (International Organization for Standardization) establishes international standards but does not specifically govern compressible-washer-type direct tension indicators. NAS (National Aerospace Standards) is focused on aerospace applications, which may not directly apply to general structural steel practices. ASCE (American Society of Civil Engineers) primarily deals with professional standards in civil engineering rather than specific product standards like those for tension indicators.