Cnc Machine G Code M Code List Manufacturing Service

Manufacturing Insight: Cnc Machine G Code M Code List

Mastering CNC Fundamentals: Precision Through Code Execution

Understanding G codes and M codes is essential for achieving optimal results in CNC machining, as these指令 form the foundational language that directs machine tool movement, spindle control, coolant management, and auxiliary functions. At Honyo Prototype, our engineering team leverages deep expertise in these critical programming elements to ensure every component meets stringent precision and repeatability standards. Our comprehensive CNC machining services—from complex 3-axis milling to high-speed 5-axis operations—are built on rigorous validation of G and M code sequences, minimizing errors and maximizing efficiency across diverse materials including aerospace alloys, medical-grade plastics, and hardened steels.

This G code M code reference list underscores our commitment to transparency and technical excellence, providing valuable insight into the precise machine control methodologies we employ. By mastering these codes, we consistently deliver prototypes and low-volume production parts with tolerances as tight as ±0.0002 inches, surface finishes down to Ra 0.8 μm, and accelerated turnaround times. For engineering teams seeking rapid validation of manufacturability and cost, Honyo Prototype offers an Online Instant Quote platform. Upload your CAD file to receive a detailed technical assessment and competitive pricing within hours—no manual submissions or delays. Accelerate your product development cycle with machining precision engineered from the ground up.

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Technical Capabilities

CNC Machine G-Code and M-Code Reference for 3/4/5-Axis Milling, Turning, and Tight Tolerance Applications

Below is a technical summary of commonly used G-codes and M-codes across multi-axis CNC milling and turning platforms, particularly relevant for high-precision machining of materials such as aluminum, steel, ABS, and nylon. These codes are standard across Fanuc-compatible controls and widely adopted by Haas, DMG MORI, Makino, and Okuma systems. Applications include tight tolerance components (±0.0005″ / ±0.0127 mm) in aerospace, medical, and industrial tooling.

Code	Type	Function	Relevance to 3/4/5-Axis Milling	Relevance to Turning	Material-Specific Notes
G00	G-Code	Rapid positioning	Used for non-cutting travel between positions in complex 3D toolpaths; essential for minimizing cycle time in 5-axis contours	Rapid traverse to safe positions during tool changes or parting	Minimizes thermal effects in thermoplastics (ABS, Nylon) by reducing non-productive time
G01	G-Code	Linear interpolation	Critical for precision linear moves in tight tolerance milling; used with high feed smoothing in 5-axis联动 (synchronized motion)	Straight turning, facing, and taper cutting	High rigidity required for steel; optimized feed rates for nylon to prevent deformation
G02	G-Code	Circular interpolation (CW)	Used for helical milling, circular tool entry, and complex contours in aluminum and steel molds	Threading, radius turning	Avoid excessive stepovers in ABS to prevent edge lifting
G03	G-Code	Circular interpolation (CCW)	As above, for counter-clockwise arcs in cavity machining	As above	Critical for smooth finishes in reflective aluminum components
G17	G-Code	XY plane selection	Default for 3-axis milling; base plane for most 2.5D operations	Used in face grooving	Less relevant in 5-axis where dynamic plane selection is used
G18	G-Code	XZ plane selection	Used in mill-turn setups	Standard for turning operations on Z-axis symmetry	Key for cylindrical features in steel and aluminum shafts
G19	G-Code	YZ plane selection	Enables side milling and complex 4-axis operations	Used in off-center drilling/milling on multitask lathes	Useful for nylon manifolds requiring perpendicular ports
G20	G-Code	Inch units	Required for U.S. aerospace and automotive prints	Common in imperial-based turning shops	Essential when matching legacy tooling for steel components
G21	G-Code	Metric units	Standard in European and medical device manufacturing	Widely used globally	Preferred for precision nylon gears with metric pitch
G28	G-Code	Return to home via reference point	Used for safe tool retraction in 5-axis to avoid collisions	Tool change positioning	Critical when switching tools for multi-material prototypes
G40	G-Code	Cutter radius compensation off	Disables compensation before complex 5-axis moves	Ends compensation after finishing cuts	Prevents overcuts in thin-wall aluminum parts
G41	G-Code	Cutter radius compensation left	Used with 3-axis contouring; caution required in 5-axis	Rough/finish turning with offset	Improves edge accuracy in ABS enclosures
G42	G-Code	Cutter radius compensation right	As above	As above	As above
G43	G-Code	Tool length compensation	Mandatory for multi-tool 4/5-axis programs; uses H-code	Applies to turret tools in mill-turn centers	Ensures depth accuracy in deep pockets (steel) and shallow cuts (nylon)
G49	G-Code	Cancel tool length compensation	Used before setup changes	Rarely used; typically overridden	Safety measure during material transitions
G54–G59	G-Code	Work coordinate systems	Essential for multiple fixtures in 3+ axis workholding	Multiple part setups on chuck/faces	Allows quick switch between aluminum and steel workpieces
G68	G-Code	Coordinate rotation	Enables angular feature machining without re-fixturing in 4-axis	Rotational indexing on C-axis	Reduces setups for nylon manifolds with angled ports
G68.2	G-Code	3D coordinate rotation	Core for 5-axis simultaneous milling; aligns toolpath to angled surfaces	Advanced mill-turn with B/C-axis	Vital for aerospace titanium/steel impellers (also applicable)
G81	G-Code	Drilling cycle	Simple hole-making in 3-axis; limited in 5-axis	Peck drilling on face or OD	Use reduced feed in ABS to avoid chip clogging
G83	G-Code	Deep hole peck drilling	Critical for long-reach tools in aluminum and steel	Deep boring cycles	Prevents heat buildup in nylon; use sharp tools and air blast
G90	G-Code	Absolute programming	Standard for all tight tolerance work	Standard in turning cycles	Required for precision step-downs in steel molds
G91	G-Code	Incremental programming	Used in subroutines or local moves	Occasionally in repetitive cycles	Limited use in high-accuracy workflows
G94	G-Code	Feed per minute	Standard for milling feeds	Used in facing and turning	Optimize for thermal control in nylon (lower SFM)
G95	G-Code	Feed per revolution	Not used in milling	Essential for threading and finish turning	Critical for consistent chip load in aluminum and steel
M03	M-Code	Spindle clockwise	Standard for most milling cutters	Standard for right-hand turning	Match with climb milling in aluminum
M04	M-Code	Spindle counterclockwise	Used for left-hand tools or specific deburring	For left-hand threading	Rare; used in specialty nylon cutting tools
M05	M-Code	Spindle stop	Required before tool change or probing	After cut completion	Prevents vibration marks on mirror-finish aluminum
M06	M-Code	Tool change	Automated in 4/5-axis with tool magazines	On turret lathes with tool change command	Critical when switching between roughing (steel) and finishing (ABS) tools
M08	M-Code	Coolant on (flood)	Flood or through-spindle coolant for steel/aluminum	Coolant during cutting	Avoid in nylon (causes swelling); use air blast
M09	M-Code	Coolant off	Turn off before tool change or dry runs	After cycle end	Mandatory before machining hygroscopic materials like nylon
M19	M-Code	Spindle orientation	Aligns tool for boring bar entry or probing	Key for tool tip positioning in turning	Ensures repeatability in precision boring of steel
M30	M-Code	Program end and reset	Final code; resets program counter	End of part program	Standard for batch runs in high-mix environments

Material-Specific Machining Notes:
Aluminum (6061, 7075): High-speed machining with sharp carbide tools; use peck drilling (G83) for deep holes; climb milling (G01, M03) preferred.
Steel (4140, 1018): Lower RPMs, rigid setups, consistent coolant (M08); G76 for precision threading in turning.
ABS: Low melting point; use high rake-angle tools, air blast cooling (avoid M08), and light cuts to prevent edge melting.
Nylon (6, 66): Highly flexible; use sharp tools, high clearance angles, and low feed rates; avoid coolant; secure fixturing to prevent deformation.

This G/M-code set supports ISO and ASME-compliant manufacturing with emphasis on geometric accuracy, surface finish, and process repeatability across hybrid machining platforms.

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From CAD to Part: The Process

Honyo Prototype executes CNC machining projects through a rigorously defined workflow designed for precision, efficiency, and client transparency. The process you referenced—Upload CAD → AI Quote → DFM → Production → Delivery—accurately outlines our core stages, though it is important to clarify that G-code and M-code generation is not a standalone client-facing step but an integral technical component occurring within the Production phase. Below is a precise explanation of how these machine codes interface with our workflow.

Upon receiving a client’s CAD file upload through our secure portal, our SmartQuote™ AI system performs initial geometry analysis and material compatibility checks. This generates a preliminary cost and lead time estimate, but crucial technical validation occurs next. The file enters our collaborative Design for Manufacturability (DFM) review, where senior manufacturing engineers assess feature feasibility, tooling requirements, and potential geometric conflicts. This stage often involves direct client consultation to resolve ambiguities or suggest optimizations—reducing downstream rework.

Only after DFM sign-off does the project advance to Production. Here, our CAM programming team converts the approved CAD model into machine-executable instructions. This is where G-code (geometric motion commands) and M-code (miscellaneous machine functions like coolant activation or tool changes) are systematically generated. We utilize industry-standard CAM software (Mastercam, Fusion 360) configured to match our specific CNC machine kinematics, tool libraries, and workholding setups. Critical to our quality assurance, every G/M-code program undergoes:

1. Rigorous simulation within CAM software to verify collision avoidance and toolpath accuracy
2. Dry-run validation on the target machine using laser-probed workpiece alignment
3. First-article inspection against GD&T callouts per AS9102 standards

It is essential to note that raw G/M-code files are proprietary operational data and not standard client deliverables. Clients receive certified inspection reports, dimensional validation data, and finished parts—not machine code—to protect intellectual property and ensure process integrity. Sharing unverified G-code could risk misapplication on dissimilar equipment.

The final Delivery phase includes comprehensive documentation: material certifications, first-article reports, and shipping manifests. For complex multi-axis projects, we provide process validation summaries detailing critical parameters, though machine code remains internal. This structured approach ensures that G/M-code execution—while technically foundational—never compromises client confidentiality or part quality.

Process Stage	Key Actions	G/M-Code Relevance
Upload CAD	Secure file ingestion, format validation	Input for CAM programming
AI Quote	Automated cost/time estimation, material analysis	Preliminary tooling assumptions
DFM	Engineering review, manufacturability optimization	Finalizes tooling strategy for code generation
Production	CAM programming, G/M-code generation, machine validation	Core execution phase where codes are created and verified
Delivery	Final inspection, documentation, shipment	Code not delivered; inspection data provided instead

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Start Your Project

If you’re looking for a comprehensive CNC machine G-code and M-code list, or need expert support for your precision manufacturing projects, contact Susan Leo at [email protected].

Honyo Prototype operates a fully equipped manufacturing facility in Shenzhen, providing high-accuracy CNC machining services with full programming and technical documentation, including standardized G-code and M-code references tailored to your machining needs.

Reach out today to streamline your production workflow with reliable, factory-direct support from our engineering team.

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