CNC G-Code & M-Code Quick Reference - Searchable Mill & Lathe Guide

How It Works

1. Search or Browse

   Type a code number (G81) or keyword (drill, coolant) in the search box, or browse the full categorized list.

2. Filter by Type or Machine

   Show only G-codes or M-codes. Further filter by Mill, Lathe, or Both.

3. Expand Code Details

   Click any code card for full syntax format, parameter definitions, and usage notes.

4. Review Syntax Examples

   Every code includes real-world syntax examples with all required parameters.

5. Use Quick-Find Shortcuts

   Links to most-needed codes: Drill, Peck Drill, Tool Change, Cutter Comp, etc.

Built For

• CNC operators looking up unfamiliar codes in existing programs
• Beginning programmers learning G-code and M-code vocabulary
• Setup technicians verifying canned cycle syntax
• Manual programmers writing G-code at the control
• Instructors teaching CNC programming fundamentals
• Maintenance technicians reading programs to diagnose machine issues

Features & Capabilities

~45 G-Codes

Motion, coordinate system, canned cycles, cutter compensation, and work coordinate codes.

~15 M-Codes

Program control, spindle, tool change, coolant, subprogram calls.

Controller-Agnostic

ANSI/ISO standard codes common to Fanuc, Haas, Mazak, and other platforms.

Mill vs Lathe Tags

Each code tagged Mill, Lathe, or Both for relevance filtering.

Search and Filter

Full-text search plus category and machine type filters.

PDF Export

Export as branded PDF for machine-side posting or training binders.

Assumptions

• G-code and M-code descriptions based on ANSI/EIA RS-274-D and ISO 6983 standard code definitions
• Syntax examples formatted for Fanuc/Haas-compatible controllers, which represent the most common platform in North America
• Canned drilling cycles (G73, G76, G81-G89) assume standard modal behavior where R-plane and Z-depth remain active until canceled
• Work coordinate system codes (G54-G59) follow standard 6-offset convention; extended offsets vary by manufacturer
• M-code numbering follows Fanuc convention; Mazak, Okuma, and Siemens use different M-code assignments for some functions
• Feed rate interpretation assumes G94 (inches per minute) for milling and G95 (inches per revolution) for turning unless stated

Limitations

• Proprietary manufacturer codes (Mazak G-codes, Siemens cycles, Okuma OSP codes) are not covered
• Conversational and graphical programming interfaces (Mazak Mazatrol, Hurco WinMax) use entirely different syntax
• Advanced features (NURBS interpolation, 5-axis RTCP, high-speed machining modes) are controller-specific and not documented here
• Macro programming (Fanuc Custom Macro B, Haas macros) syntax and variables are beyond the scope of this reference
• Lathe-specific codes for live tooling, sub-spindle, and Y-axis operations vary significantly by manufacturer
• Does not include post-processor customization guidance for CAM-generated G-code output

References

1. ANSI/EIA RS-274-D - Interchangeable Variable Block Data Format for Positioning, Contouring, and Contouring/Positioning Numerically Controlled Machines
2. ISO 6983 - Numerical Control of Machines - Program Format and Definitions of Address Words
3. Fanuc Series 0i/30i/31i Operator's Manual - Programming (standard G-code and M-code reference)
4. Haas CNC Mill and Lathe Operator's Manual - G-Code and M-Code Reference
5. Machinery's Handbook, 31st Edition - CNC Programming and G-Code Reference Tables
6. Peter Smid - CNC Programming Handbook, 3rd Edition (comprehensive G-code programming reference)

Frequently Asked Questions