The V-shaped form tool used in threading has what standard cutting edge angle?

The V-shaped form tool used in threading has what standard cutting edge angle?

• A. 60 degrees
• B. 45 degrees
• C. 30 degrees
• D. 90 degrees

Answer: (A)

In threading with a V-shaped form tool, the tool must match the thread’s profile. For standard V-threads, the profile is a 60° included angle. So the form tool’s two faces meet at 60°, giving a V with 60° between its sides. This ensures the thread flanks form the correct geometry and the crest and root are cut properly. Each flank is effectively 30° from the centerline, which helps visualize why 60° is used. Choosing 30°, 45°, or 90° would not produce the standard V-thread shape—they would create a different or nonstandard form.

In threading with a V-shaped form tool, the tool must match the thread’s profile. For standard V-threads, the profile is a 60° included angle. So the form tool’s two faces meet at 60°, giving a V with 60° between its sides. This ensures the thread flanks form the correct geometry and the crest and root are cut properly. Each flank is effectively 30° from the centerline, which helps visualize why 60° is used. Choosing 30°, 45°, or 90° would not produce the standard V-thread shape—they would create a different or nonstandard form.