Understanding Tools for Scribing Parallel Lines

The question asks which tool is used to scribe lines parallel to the edges of a part. Let's look at the functions of the tools provided in the options.

Examining the Options

• Vernier Calipers: Vernier calipers are precision measuring instruments used to measure linear dimensions such as length, depth, and inside or outside diameters. They are not designed for scribing lines, especially not parallel to edges.
• Screw Gauge: A screw gauge is used to measure very small lengths, typically thicknesses of thin sheets or diameters of fine wires. It is a precision measuring tool, not a scribing tool.
• Divider: Dividers are used for transferring measurements or for scribing circles and arcs. While they have pointed legs used for marking, they are not specifically designed to scribe lines parallel to an edge with a consistent offset.
• Hermaphrodite: Hermaphrodite calipers (also known as odd-leg calipers or Jenney calipers) are scribing tools. They have one leg shaped like a caliper leg with a heel or foot, and the other leg is a sharp point like a divider leg. The leg with the foot is guided along the edge of a workpiece, while the pointed leg scribes a line parallel to that edge at a set distance. This tool is specifically designed for the task described in the question.

Based on the functions of these tools, the Hermaphrodite caliper is the appropriate tool for scribing lines parallel to the edges of a part.

Therefore, the tool used to scribe lines parallel to the edges of a part is the Hermaphrodite caliper.