February Test of the Month: CNC Skills

CNC stands for Computer Numerical Control. That used to just be Numerical Control, before computers were a thing. And we mean way before computers were a thing, like, the nineteenth century.

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Automation of machine tools began in the 1830s, when one inventor, Thomas Blanchard (who also invented the first car, by the way), created a gun-copying lathe that operated with cams and “played” the machine the same way cams played cuckoo clocks and musical boxes.

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By World War I, complex cam-driven machines could duplicate parts, but they were not programmable. Changing the part design required physical retooling of cams or templates. However, these advancements did set the stage for true Numerical Control machines, which emerged in the 1940s and ‘50s due to WWII and then the Cold War.

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Before digital screens, NC coordinates were stored on punched tape, which would be fed into the machine and program it to execute a machining task.

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And finally, in the 1970s, the “C” arrived — COMPUTERS.

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These days, CNC machines are everywhere, carving and cutting aerospace technology, medical devices, and even sculptures, in addition to consumer goods like guitars, furniture, and car parts.

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But we don’t need to go all into the history, even though we just did. What we really need to know is why and how you should test the skills of CNC machinists. 

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Here’s why you should verify that a CNC machinist knows how to set up a design in a computer software, translate it to code for the machine, and ensure the machine is operating how it’s supposed to.

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Why test CNC skills?

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The day-in-the-life of a CNC machinist involves a lot of moving parts (pun very much intended). CNC work blends blueprint reading, math, CAD/CAM literacy, machine setup, tool selection, and quality control. 

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Not only does a CNC machinist need to know what G-code is and what it represents, but they have to make sure the machine is translating that code properly, and make sure all the physical parts of the machine are in working order, too.

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It’s a true example of gray collar work — combining both digital understanding and hands-on machine operation. Mechanics need to know how to troubleshoot both software and hardware.

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Testing CNC skills helps employers ensure that candidates can safely and accurately operate complex, software-driven machines while producing parts that meet exact specifications. 

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And by assessing these skills upfront, companies reduce costly errors, scrap, and downtime, improve shop-floor safety, and hire operators who can adapt to modern, increasingly automated manufacturing environments.

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What is a CNC machine?

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Unlike 3D printing, CNC is a negative process in that it removes material instead of adding it. It essentially carves out shapes out of large pieces of material. That could mean cutting, drilling, milling, or shaping materials like metal, plastic, or wood. 

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Instead of being operated entirely by hand, the machine follows digital design files — typically created in CAD and translated into CAM instructions — to move tools along exact paths with high accuracy and repeatability. 

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You design a part on a computer, then a computer translates that design into coordinates, then the machine follows those coordinates to shape raw material (metal, plastic, wood, etc.) into a finished part.

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CNC machines are used to produce everything from one-off prototypes to mass-produced parts, making them essential in modern manufacturing.

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Who uses CNC machines?

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CNC machines are used across a wide range of industries anywhere precision, repeatability, and efficiency matter. 

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In traditional manufacturing and industrial settings, CNC machinists, operators, and technicians run mills, lathes, and routers to produce metal and plastic parts, tools, and fixtures. Aerospace, automotive, and defense manufacturers rely heavily on CNC machining to make high-tolerance components like engine parts, airframe pieces, and precision housings, where even tiny deviations can cause major failures. 

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Medical and dental manufacturers also depend on CNC machines to produce implants, prosthetics, and surgical tools that must meet strict regulatory and quality standards.

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Beyond large factories, CNC machines are widely used in product design, prototyping, woodworking, and education. 

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Engineers and product designers use CNC machining to rapidly prototype parts before mass production, while furniture makers, cabinet shops, and architectural firms use CNC routers to create detailed, repeatable wood components at scale. 

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At the same time, smaller job shops, makerspaces, and trade schools increasingly use desktop CNC machines to train students and support small-batch or custom work. 

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Together, these uses reflect a broader shift toward “gray-collar” roles that blend hands-on machine operation with digital skills like CAD/CAM software, programming, and quality control.

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What does the CNC Skills test cover?

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The CNC Skills Test covers a broad range of topics, spanning both foundational concepts and more advanced, hands-on knowledge. It’s designed to assess not just whether a candidate knows what CNC machining is, but whether they understand how it actually works in practice.

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Here’s what we cover, from basic CNC fundamentals to advanced mechanical and machining knowledge:

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• General CNC Machining Knowledge
• Work-Holding
• Shop & Workplace Safety
• GD&T/Blueprint Reading
• Quality Control/Inspection
• Programming
• Machining Math

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Test format

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The CNC Skills test is a combination of true/false, multiple choice, select-all-that-apply, and more. Some questions have visuals to accompany them, such as blueprints or setups.

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Complementary questions

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If you’re testing for a CNC Mechanic, you might also want to test for adjacent mechanical and technical skills that support reliable machine operation and long-term equipment health, such as:

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• Blueprint Reading
• Manufacturing Math
• Assembly Skills
• AutoCAD
• Autodesk Revit MEP
• Industrial Math
• Mechanical Aptitude
• SolidWorks
• Reading Micrometers and Calipers

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Why use the CNC skills test?

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Resumes and interviews often can’t verify hands-on abilities like interpreting G-code, setting up tools, understanding tolerances, or troubleshooting errors, but a skills test can. 

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This approach supports merit-based hiring, shortens time to productivity, lowers training and safety risks, and helps manufacturers confidently place the right people into increasingly complex, gray-collar CNC roles.

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Using a CNC skills test gives employers a consistent, objective way to evaluate whether candidates actually have the technical and digital competencies the role requires — before they ever touch a machine.