A journeyman test does not waste time asking what G01 is. It assumes you know the basics and probes the layer that separates an operator from a more advanced machinist: compensation, offsets, cycles, and the judgment to read or fix a whole program.
The deeper scope
Where an operator test checks the common codes, a journeyman test expects you to explain and apply:
- Tool length compensation (
G43) and how an offset value changes the Z move. - Cutter compensation (
G40toG42) and why it matters for finished dimensions. - Work offsets (
G54toG59) and how part zero is established. - Canned cycles such as drilling (
G81) and tapping (G84), including the role of their parameters. - Subprograms and program flow.
- Reading or correcting a full program, not just single lines.
Operator vs journeyman scope
| Topic | Operator test | Journeyman test |
|---|---|---|
| Common motion codes | Recall | Assumed |
Compensation (G43, G41/G42) | Recognize | Explain and apply |
| Work offsets | Know they exist | Set and reason about |
| Canned cycles | Aware | Explain parameters |
| Whole-program reading | Basic | Confident, including fixes |
How to prepare
The basics must be automatic so your attention is free for the harder material. Keep the common G-codes and common M-codes sharp with the method in beginner CNC code practice, make sure the modal behavior is second nature, then study compensation and cycles on real programs. For the credential path, see CNC machinist certification test prep. Two advanced examples worth studying are M98 and M99 subprograms and a lathe bar puller program. A free tool like G-Code Sprint keeps the foundation solid so study time goes to the advanced topics.
Bottom line
A journeyman G-code test probes compensation, offsets, canned cycles, and full-program reading. Lock in the basics so they are automatic, then study the deeper concepts and practice on complete programs.
Sources
- LinuxCNC G-code reference (compensation, canned cycles)
- NIMS (National Institute for Metalworking Skills)
- CNCCookbook: G-code and M-code cheat sheet
Frequently asked questions
How is a journeyman G-code test different from an operator test?
An operator test checks that you can read the common codes and run a job. A journeyman test assumes that and goes deeper: compensation, work offsets, canned cycles, subprograms, and reading or fixing a full program with confidence.
What advanced G-codes are on a journeyman test?
Tool length compensation (G43), cutter compensation (G40 to G42), work offsets (G54 to G59), and canned cycles such as drilling (G81) and tapping (G84), plus subprogram calls. You are expected to explain what they do, not just name them.
How do I study for a journeyman machinist test?
Make the basics automatic first, then study compensation and canned-cycle concepts and practice on real programs. A free tool like G-Code Sprint keeps the foundational recall sharp so your study time goes to the harder material.
G-Code Sprint is a study and practice tool only. Always follow your instructor, employer, machine manual, and shop safety procedures.