What is required for heavy-hex nuts according to the specifications?

Heavy-hex nuts are critical components in structural steel applications, and their specifications are defined by industry standards to ensure safety and reliability. The requirement for heavy-hex nuts to meet ASTM A563 is crucial because this specification outlines the material properties, mechanical performance, and manufacturing processes necessary for these fasteners. ASTM A563 covers various grades of nuts, including those made from carbon and alloy steels, which ensure they can withstand the stresses and loads that occur in structural applications.

By conforming to ASTM A563, heavy-hex nuts are assured of consistent quality, strength, and corrosion resistance, which are essential for maintaining the integrity of any construction project. This standardization helps in ensuring compatibility with other components of the bolted joint, leading to safer and more dependable structures.

The other options refer to specific conditions that may apply to certain types of nuts, but they do not represent the comprehensive requirement that ASTM A563 embodies for heavy-hex nuts. For instance, while some heavy-hex nuts might be made of forged steel or be zinc-plated, these characteristics are not universally required under the specification, and the same applies to the use of stainless steel.