In technical drawings, the center line is used to represent what?

In technical drawings, the center line is used to represent what?

• A. Axis of symmetry
• B. Edge of part
• C. Surface finish
• D. Hole center

Answer: (A)

Center lines show the axis of symmetry of a part and the centers of cylindrical features. They’re drawn as alternating long and short dashes so they stand out from edges and other lines. This helps you understand where features are centered, align different views, and locate holes or bores across the drawing. They aren’t used to indicate an outer edge or surface finish—that information is shown with other lines and symbols. Through the hole or bore, the center line marks its axis, making the feature’s location and orientation clear in the overall design.

Center lines show the axis of symmetry of a part and the centers of cylindrical features. They’re drawn as alternating long and short dashes so they stand out from edges and other lines. This helps you understand where features are centered, align different views, and locate holes or bores across the drawing. They aren’t used to indicate an outer edge or surface finish—that information is shown with other lines and symbols. Through the hole or bore, the center line marks its axis, making the feature’s location and orientation clear in the overall design.