ASME B18.31.2 is the definitive American standard for Continuous Thread Studs (Inch Series). Often referred to in the field as "All-Thread Studs," this standard specifies the dimensional requirements for studs that are threaded over their entire length, tailored for high-strength industrial bolting.

Unlike generic threaded rods, ASME B18.31.2 studs are typically manufactured from high-performance alloys and are designed to be used with two nuts to create a high-tension clamping force. They are foundational components in flange bolting for piping systems, pressure vessels, and heavy structural assemblies where reliability under thermal expansion and high pressure is non-negotiable.

The technical focus of ASME B18.31.2 is Load Uniformity and Length Accuracy. By providing a continuous thread profile, these studs allow for precise adjustment of the nut engagement on both ends, which is critical for achieving uniform gasket compression in circular flange patterns. The standard specifies point requirements—typically chamfered or rounded—to protect the thread integrity during the heavy-duty installation common in oil and gas refineries.