What included angle do V-shaped symmetrical threads have?

What included angle do V-shaped symmetrical threads have?

• A. 60°
• B. 45°
• C. 30°
• D. 90°

Answer: (A)

The included angle is the angle between the two sides of the thread profile. For a V-shaped symmetrical thread, the two sides are mirror images, so they form a total angle of 60 degrees, with each flank about 30 degrees from the centerline. This 60° standard is what lets nuts and bolts with a V-thread mesh properly. Angles like 45°, 30°, or 90° would be nonstandard and won’t fit typical fasteners designed for 60° threads.

The included angle is the angle between the two sides of the thread profile. For a V-shaped symmetrical thread, the two sides are mirror images, so they form a total angle of 60 degrees, with each flank about 30 degrees from the centerline. This 60° standard is what lets nuts and bolts with a V-thread mesh properly. Angles like 45°, 30°, or 90° would be nonstandard and won’t fit typical fasteners designed for 60° threads.