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CNC Machinist Practice Test

Check what you know about the CNC machinist job with 15 free questions and instant explanations.

Updated By the Career Education Institute Curriculum Team
About this practice test

15 multiple-choice questions on CNC machinist knowledge, safety and vocabulary. Submit to see your score and explanations, or open any question’s answer as you go. Nothing is saved or shared.

Question 1 of 15What does G54 typically represent?
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Answer: A work offset. G54 is the first work coordinate system.

Question 2 of 15RPM equals:
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Answer: (SFM × 3.82) ÷ diameter. That’s the standard spindle speed formula.

Question 3 of 15First-article inspection is done:
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Answer: On the first part of a setup. It verifies the setup before production.

Question 4 of 15M-codes control functions such as:
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Answer: Spindle and coolant. M-codes are miscellaneous machine functions.

Question 5 of 15Tolerance means:
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Answer: Allowed variation from a dimension. Tolerance defines acceptable variation.

Question 6 of 15Which term matches this definition: “Computer-aided manufacturing software that creates toolpaths.”
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Answer: CAM. CAM: Computer-aided manufacturing software that creates toolpaths.

Question 7 of 15What does “Chip load” mean?
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Answer: The thickness of material removed per cutting edge per revolution.. Chip load: The thickness of material removed per cutting edge per revolution.

Question 8 of 15Which term matches this definition: “A stored value compensating for each tool’s length.”
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Answer: Tool length offset. Tool length offset: A stored value compensating for each tool’s length.

Question 9 of 15What does “Work offset” mean?
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Answer: The reference position (such as G54) that defines part zero.. Work offset: The reference position (such as G54) that defines part zero.

Question 10 of 15Which term matches this definition: “A rotating cutting tool used on milling machines.”
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Answer: End mill. End mill: A rotating cutting tool used on milling machines.

Question 11 of 15What does “Micrometer” mean?
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Answer: A precision measuring tool, typically accurate to 0.0001 inch.. Micrometer: A precision measuring tool, typically accurate to 0.0001 inch.

Question 12 of 15Which term matches this definition: “Removing sharp edges and burrs after machining.”
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Answer: Deburring. Deburring: Removing sharp edges and burrs after machining.

Question 13 of 15What does “First-article inspection” mean?
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Answer: A full inspection of the first part produced in a setup.. First-article inspection: A full inspection of the first part produced in a setup.

Question 14 of 15Which term matches this definition: “The allowable variation from a specified dimension.”
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Answer: Tolerance. Tolerance: The allowable variation from a specified dimension.

Question 15 of 15What does “SFM” mean?
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Answer: Surface feet per minute: the cutting speed at the tool’s edge.. SFM: Surface feet per minute: the cutting speed at the tool’s edge.

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