Millwright Level 1 Practice Exam

What is the included angle that should be ground on the point of a center punch?

1. 45 degrees

2. 60 degrees

3. 90 degrees

4. 120 degrees

The correct answer is: 90 degrees

The included angle that should be ground on the point of a center punch is 90 degrees. This angle is designed to create a sharp point that can create a dimple or indentation in metal surfaces without the risk of slipping. The 90-degree point allows the punch to create a well-defined starting point for drilling, which is essential in obtaining accurate and precise holes. When the center punch is struck, the 90-degree angle facilitates the effective transfer of force to the material, ensuring that the punch penetrates the surface cleanly. Other angles, such as 45 or 60 degrees, would create a less effective point for this purpose, possibly leading the punch to slip or not produce a sufficiently sharp indentation. A 120-degree angle would be too blunt for the intended use of a center punch, making it ineffective for precise marking on hard materials. Understanding this specific angle reinforces the importance of tool geometry in achieving desired outcomes in machining and fabrication tasks.