The professional who turns a block of metal and a drawing into a precision part. Here we explain it without the fluff: what they do, which machines they work with and how they differ from a lathe operator or a fitter.
A machinist is the professional who makes precision metal parts by removing material (what is known as chip removal) with machine tools such as the lathe and the milling machine, today almost always computer numerical control (CNC). They interpret drawings, program and set up the machine, adjust the cutting tools, machine the part and check its dimensions with metrology instruments. In Spain you train through the Intermediate-level VET diploma in Machining, in the Mechanical Manufacturing family.
A machinist is the person who shapes metal parts —or parts made of other hard materials such as certain technical plastics— by removing material from a raw workpiece until it has the exact geometry and dimensions called for by a drawing. That work of taking away material in the form of chips is known as machining by chip removal, and it is the essence of the trade: no material is added or melted, it is removed with precision until the desired dimension is reached.
The key word is precision. A machined part may need to meet tolerances of hundredths or even thousandths of a millimetre, because it will later be assembled together with other parts inside an engine, a gearbox or a landing gear. The machinist does not just "make holes": they guarantee that every measurement is within the tolerance the design allows. That is why the trade combines manual skill, knowledge of materials, technical reading and, increasingly, programming.
In Spanish vocational training, the reference figure is the Machining Technician, an Intermediate-level VET programme within the Mechanical Manufacturing professional family. Its general competence consists of manufacturing parts through machining processes, both with conventional machine tools and with numerical control machines, complying with quality, safety and environmental protection standards.
Although every workshop is different, a machinist's day usually revolves around a fairly recognisable sequence. It is not just pressing a button: there is a preparation phase and a quality control phase that are worth as much as the cutting itself.
Under the umbrella of chip removal, several processes coexist. A machinist rarely masters just one; the norm is to combine them depending on the part. These are the most common:
The part rotates held in the spindle while a fixed tool removes material from it. It is the ideal process for parts of revolution: shafts, bushings, screws, pulleys. It is done on the lathe.
Here it is the tool that rotates (the milling cutter) while the part moves. It allows you to generate flat surfaces, slots, pockets, contours and complex shapes in three or more axes. It is done on the milling machine.
It makes holes with a rotating drill bit. Although it may seem simple, controlling the position, diameter and perpendicularity of the hole is also part of the trade, and it is usually combined with reaming or threading.
It uses an abrasive wheel to achieve very fine finishes and very tight tolerances, normally as a final step after other machining operations or a heat treatment.
The two mother machines of the workshop are still the lathe and the milling machine. For decades they were operated manually, with handwheels and cranks, and those machines are called conventional. Today most of the work is done with computer numerical control (CNC): the machine runs a program that defines toolpaths, speeds and tool changes with a repeatability impossible to match by hand.
CNC has not eliminated the trade, it has shifted it. Today's machinist spends less time turning cranks and more time interpreting the drawing, generating the toolpath, simulating the program and controlling quality. Knowing conventional machines is still valuable —it teaches the fundamentals of cutting—, but mastering CNC is what opens up the best opportunities. If you want to go deeper into this, we have a guide dedicated to the CNC lathe and milling machine.
These terms are often mixed up, but they do not mean exactly the same thing. The distinction has to do with specialisation:
Put another way: lathe operators and milling operators are machinists specialised by type of machine, while the fitter deals mainly with assembly and fine fitting. In a small workshop, one and the same person may do everything; in large industry, the roles are more separated.
Machining is cross-cutting: almost any product with precision metal parts passes, at some point, through a machining workshop. The three big destinations of the trade are:
From here, if the trade interests you, the natural next step is to see how to become a machinist and get a realistic idea of how much the sector pays.
Keep going here
You already know what a machinist is. These guides take you to the next step, all with verified data.
Intermediate-level VET, professional certificates, what you study and how to get in without prior qualifications.
See the path →Ranges by experience and role (operator, CNC programmer, workshop manager), with data from salary sources.
See salaries →How numerical control works, basic G-code, cutting tools and good workshop practices.
Learn CNC →The complete guide to machining: what it is, how to train, salary and CNC, with the "machine to size" mini-game.
Go to the home →Frequently asked questions
They make precision metal parts by removing material through chip removal. In practice they interpret drawings, set up and program the machine (lathe, milling machine or CNC), adjust the cutting tools, machine the part and check its dimensions with metrology instruments to ensure it is within tolerance.
"Machinist" is the general term for someone who makes parts by chip removal and can handle several machines and processes. "Lathe operator" is a machinist specialised on the lathe. In the same way, a "milling operator" specialises on the milling machine. The fitter, by contrast, is more dedicated to the assembly and manual fitting of parts.
The most common route is the Intermediate-level VET in Machining, in the Mechanical Manufacturing professional family, which trains the Machining Technician. There are also related professional certificates. You can see it in detail in our guide on how to become a machinist.
Not necessarily. Today most industrial work is done with numerical control (CNC) machines, but many workshops still use conventional machines, especially for one-off parts or repairs. A good machinist understands both worlds: the fundamentals of manual cutting and CNC programming.
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