In pattern development, what does a centerline indicate?

In pattern development, what does a centerline indicate?

• A. The axis of symmetry or bend location.
• B. The location of dim notes.
• C. The seam gap width.
• D. Hole center positions.

Answer: (A)

Centerlines in pattern development show the line of symmetry and where bends or folds are to occur. This reference line tells you that the part is meant to be mirrored across it, so features on one side can be laid out as a mirror image on the other. When you transfer the pattern to sheet metal, bending along or around that line creates the correct, symmetric shape, with equal dimensions on both sides. It’s a guide for how the piece will form, not a marker for where dim notes, seam gaps, or individual hole centers must be placed. Those details come from separate marks and measurements, while the centerline anchors the overall symmetry and bend location.

Centerlines in pattern development show the line of symmetry and where bends or folds are to occur. This reference line tells you that the part is meant to be mirrored across it, so features on one side can be laid out as a mirror image on the other. When you transfer the pattern to sheet metal, bending along or around that line creates the correct, symmetric shape, with equal dimensions on both sides. It’s a guide for how the piece will form, not a marker for where dim notes, seam gaps, or individual hole centers must be placed. Those details come from separate marks and measurements, while the centerline anchors the overall symmetry and bend location.