Which thread form generally has a 60° included angle?

The thread form that generally has a 60° included angle is the V-shaped thread. This design is commonly used in various fasteners and screw threads, such as those found on bolts and nuts. The 60° angle is advantageous because it provides a good compromise between strength and ease of manufacturing. It allows for efficient transmission of force and minimizes the risk of stripping, which can occur with threads that have steeper angles.

In contrast, square threads have an included angle of 90°, which provides good efficiency for driving forces but is more challenging to manufacture. Flat threads generally have a very shallow angle, and while they can provide a large surface area for contact, they do not engage well under tensile load. Acme threads have a 29° included angle, which makes them more suitable for power transmission applications but distinctly different than V-shaped threads.

Understanding these distinctions is essential, as each thread form serves specific purposes based on the mechanical requirements and manufacturing constraints.