Red Seal Machinist Practice Exam

What does the term "runout" refer to?

1. The static balance of the machine

2. The amount of deviation or wobbling of the tool or workpiece from its intended path

3. The speed at which the tool rotates

4. The thermal expansion of materials during cutting

The correct answer is: The amount of deviation or wobbling of the tool or workpiece from its intended path

Runout specifically refers to the amount of deviation or wobbling of a tool or workpiece from its intended path during machining operations. It is an important concept because excessive runout can lead to inaccuracies in machining, such as poor surface finish or dimensional errors. For example, if a tool is not running true in the spindle, it can produce parts that do not meet specifications, which affects quality and can lead to increased waste and rework. Understanding runout is crucial for machinists, as it can result from factors such as improper setup, wear in bearings, or an untrue workpiece. Monitoring and minimizing runout ensures better precision and contributes to the overall functionality and longevity of the machinery and components being produced.