Which line type marks the center axis and symmetry on drawings?

Which line type marks the center axis and symmetry on drawings?

• A. Plot
• B. Centerline
• C. Object line
• D. Section

Answer: (B)

Centerline is used to mark the center axis and symmetry in drawings. It indicates the axis of cylindrical features, centers of holes or arcs, and planes of symmetry so you can locate true centers across views. It’s drawn as alternating long and short dashes and should extend through the feature to show alignment. This distinguishes it from object lines, which are solid outlines of visible edges, and section lines, which show where a cut is made and are typically hatch lines. Centerlines are the dedicated way to convey symmetry and central axes in a drawing.

Centerline is used to mark the center axis and symmetry in drawings. It indicates the axis of cylindrical features, centers of holes or arcs, and planes of symmetry so you can locate true centers across views. It’s drawn as alternating long and short dashes and should extend through the feature to show alignment. This distinguishes it from object lines, which are solid outlines of visible edges, and section lines, which show where a cut is made and are typically hatch lines. Centerlines are the dedicated way to convey symmetry and central axes in a drawing.