What Is a CNC Machinist?

A CNC machinist makes parts according to the dimensions and tolerances specified on engineering drawings. The work centers on computer-controlled machine tools, most commonly CNC mills and lathes.

What Does a CNC Machinist Do?

Responsibilities vary by employer and production environment. Machine shops may manufacture medical, aerospace, government, industrial, or aftermarket components.

In a production shop, a machinist may load many parts onto fixtures, monitor long machining cycles, remove completed parts, and deburr them. A single production job may continue for months.

Smaller job shops generally handle shorter runs and more frequent changeovers. Machinists in these environments may set up a different part each day, prepare jobs, and correct programs when necessary.

Typical duties include:

• Loading and removing workpieces
• Inspecting finished parts to confirm that they meet specified tolerances
• Troubleshooting machining and quality problems
• Adjusting programs, feeds, and speeds
• Deburring completed parts

Operator, Machinist, and Programmer Responsibilities

An entry-level operator may primarily load parts and run established processes. With additional skill and experience, a machinist can take responsibility for setups, inspection, process adjustments, and program edits.

CNC programming is a more advanced specialization. Programmers need a strong understanding of CNC code, machining processes, tooling, and part geometry. They may write programs manually or create toolpaths with CAD/CAM software.

Learning CNC Programming

Programming skills can be developed through guidance from experienced machinists, hands-on shop experience, or machining courses at a technical school. Becoming proficient in manual programming and CAD/CAM software takes sustained practice, but it can open the door to more advanced responsibilities.