What term describes the angle included between the sides measured in an axial plane in a screw thread?

The term that accurately describes the angle included between the sides measured in an axial plane of a screw thread is the "Angle of thread." This angle is fundamental to understanding the geometry of screw threads, as it determines how the thread interacts with mating components. The angle of thread influences both the strength of the screw and its ability to convert rotational motion into linear motion, which is essential in many mechanical applications.

In practical terms, this angle is critical when designing fasteners and understanding load distribution. It impacts how the threads engage with nuts or tapped holes, directly affecting performance and safety in assemblies.

Although terms like Helix angle and Half angle might resonate with aspects of thread geometry, they refer to different ways of measuring properties related to the thread, such as the thread's inclination around the shaft or measuring the angle from a different perspective. Thus, "Angle of thread" is the specific terminology used for the angle measured in an axial plane between the sides of the screw thread.