Under what specification can black high-strength bolts be reused once approved?

The correct answer highlights the specific standards applicable to black high-strength bolts, particularly emphasizing ASTM A325. This specification details the requirements for high-strength bolts, including their material properties, manufacturing processes, and testing protocols necessary for their use in structural connections.

When high-strength bolts conforming to ASTM A325 are approved, the specification allows for their reuse under certain conditions. These conditions often involve assessing the integrity of the bolts, checking for any visible damage or deformation, and ensuring that the bolts can still meet the required load-bearing demands. Importantly, the reuse process must follow established guidelines to ensure safety and structural performance.

On the other hand, other options like ASTM A490 represent a different category of high-strength bolts with distinct requirements and conditions for use, including their suitability for specific applications and environments. The AISC Specification generally refers to the broader guidelines and standards for structural steel design and fabrication but does not specifically address bolt reuse in the same manner as ASTM A325. ISO 9001 Standards focus primarily on quality management systems and do not pertain specifically to structural bolt reuse criteria.

Thus, the reference to ASTM A325 is essential for understanding the context and standards related to the reuse of black high-strength bolts in construction and structural applications.