Jigs vs. fixtures vs. gauges: primary purpose of a jig In production tooling, what is the main function of a <em>jig</em>?

Introduction / Context:
Production tooling uses jigs, fixtures, and gauges to improve accuracy, speed, and interchangeability. Each has a distinct role in the manufacturing system.

Given Data / Assumptions:

• Common hole-making operations (drilling, reaming, tapping).
• Need for repeatable tool location without extensive layout/marking.

Concept / Approach:
A jig locates and holds the workpiece and additionally guides the tool (via drill bushings), ensuring precise hole location. A fixture locates and holds but does not guide the tool; it is used for processes like milling or turning. A gauge checks dimensions/geometry after processing.

Step-by-Step Solution:
Identify the need to guide the tool → select jig.If only holding/supporting the work → fixture.For inspection → gauge.

Verification / Alternative check:
Standard manufacturing texts define jigs by their tool-guiding function through hardened bushings.

Why Other Options Are Wrong:

• (B) describes fixtures (no tool guidance).
• (C) describes gauges, not jigs.
• (E) is a coolant delivery system function, unrelated to jigs.

Common Pitfalls:
Using “jig” and “fixture” interchangeably; omitting bushings leading to rapid wear in guide holes.

Final Answer:
To hold the work and also guide the cutting tool in drilling, reaming, or tapping