What indicates the threading direction on a malleable coupling?

The threading direction on a malleable coupling is indicated by the rib count and stamped markings. These features are specifically designed to provide clear visual cues regarding the direction in which the threads are cut, which is crucial for ensuring proper alignment and secure connections when joining piping systems.

In the construction and plumbing industries, understanding the threading direction is essential to avoid cross-threading or improper coupling, which can lead to leaks and system failures. The markings and rib count give immediate, intuitive information to the installer, saving time and reducing the chance of errors when working with various piping materials.

Other options, while they may pertain to aspects of the coupling, do not provide relevant information about the threading direction. Therefore, focusing on rib count and stamped markings is the most effective way to identify how the coupling should be oriented during installation.