JLCCNC Blog

CNC Programming

What is G Code and M Code: Differences, Uses & Examples

Key Takeaways G codes define tool motion and machining modes, while M codes control auxiliary functions such as spindle operation, coolant, and program stops. G codes are mostly modal (they stay active until changed), whereas M codes are a mix of modal and non-modal commands. The exact meaning of a code varies by controller and machine type, so you must verify against the machine's programming manual. Most production programs are generated by CAM software and then verified against the specific machine......

Oct 29, 2026

CNC Programming

CNC M Code List: Functions and Common Uses

Key Takeaways G codes define motion and machining modes, while M codes trigger auxiliary machine functions. Common M codes include M00/M01 for program stops, M03/M04/M05 for spindle control, and M08/M09 for coolant control. M-code assignments for functions such as chuck control, pallet changes, and live tooling vary by machine builder and model. Always verify machine-specific M codes against the target machine's programming manual before running a CNC program. An M code (miscellaneous code) is a CNC p......

Oct 29, 2026

Sheet Metal Fabrication

Sheet Metal Enclosure Design: Complete Guide to Materials, Thickness, and Manufacturing

What Is a Sheet Metal Enclosure Design (AI generated) Technician holding an open sheet metal enclosure box with internal mounting features inside a modern fabrication workshop. An enclosure is essentially the protective chassis for a system’s sensitive internals. Fabricators take flat sheet stock, cut and bend it, and then assemble a rigid housing to keep PCBs, drives, and wiring safe from environmental factors like dust or vibration. These boxes are functional parts of the electrical design. They han......

Oct 28, 2026

Design Tips & Best Practices

Circularity GD&T Explained

Key Takeaways Circularity controls how round each cross-section is on a cylindrical, conical, or spherical surface. Each cross-section is checked separately. Circularity doesn't control taper, axis straightness, or alignment between sections. No datum is needed because circularity controls the shape of the feature itself. The circularity tolerance zone is bounded by two concentric circles whose radial separation equals the specified tolerance. Each circular element must fit within its own zone, evalua......

Oct 23, 2026

Industry Use Cases

CNC Motorcycle Parts: Types and How They Are Made

Key Takeaways CNC motorcycle parts are custom or production components machined from CAD models to achieve specified mounting interfaces, dimensions, and surface features. CNC is well suited to brackets, covers, spacers, bushings, and low-volume replacements, but parts affecting braking, steering, suspension, wheel retention, or rider safety require engineering validation beyond machinability. CNC milling suits brackets, covers, and parts with complex profiles, while CNC turning is used for shafts, bu......

Oct 23, 2026

Tools & Cutting Instruments

Broken Tap Removal Methods and When to Use Them

Key Takeaways Method Best suited for Main limitation Pliers Exposed tap stub with enough material to grip May crush the stub or damage the surrounding surface Tap extractor Accessible flutes and a fragment that can still rotate Extractor prongs can break if the tap is seized Left-hand drill bit A centered fragment that is not fully seized May back out the fragment, but is not a reliable way to drill through hardened tap steel Carbide end mill Controlled removal on a rigid, accurately aligned machine M......

Oct 20, 2026