| Aluminum 6061 | Aluminum Alloy | Lightweight, corrosion resistant, good machinability, and moderate structural strength. | Provides a strong enclosure with low mass and can be machined efficiently for precise openings, mounting holes, and internal cavities. | Electronic housings, control boxes, instrumentation enclosures, and lightweight machine covers. | Bead blasting Anodizing Powder coating | Thin walls may deform from clamping forces. Anodizing can slightly affect final dimensions, especially in small bores and threaded features. |
| Aluminum 7075 | High-Strength Aluminum Alloy | Higher strength-to-weight ratio than common general-purpose aluminum alloys, with good machinability. | Useful when a CNC box must remain lightweight while resisting higher mechanical loads and vibration. | Aerospace-style equipment housings, robotic components, structural instrument cases, and high-load covers. | Anodizing Bead blasting Chemical conversion coating | It generally has lower corrosion resistance than 6061, so protective finishing may be needed for demanding environments. |
| Stainless Steel 304 | Austenitic Stainless Steel | Excellent corrosion resistance, good toughness, and strong resistance to many industrial environments. | Supports durable precision boxes where cleanliness, moisture resistance, and long service life are important. | Food-processing equipment, laboratory enclosures, medical equipment housings, and outdoor control boxes. | Brushed finish Passivation Electropolishing | Work hardening can occur during machining. Sharp, properly maintained tools and suitable cutting conditions help maintain accuracy. |
| Stainless Steel 316 | Molybdenum-Bearing Stainless Steel | Very good corrosion resistance, particularly against chlorides and marine-related exposure. | Offers reliable protection for precision CNC boxes used in humid, saline, chemical, or washdown conditions. | Marine electronics, chemical-processing equipment, outdoor instrumentation, and hygienic enclosures. | Passivation Electropolishing Brushed finish | It is more difficult to machine than aluminum and may require careful heat management to limit distortion and work hardening. |
| Mild Steel A36 | Carbon Steel | Good weldability, high availability, and useful structural strength at a relatively low material cost. | Suitable for robust CNC boxes and cabinets where weight is less important than rigidity and impact resistance. | Industrial machine guards, electrical cabinets, brackets, protective housings, and workshop equipment. | Powder coating Paint Zinc plating | Unprotected steel can rust. Corrosion protection and proper storage are important after machining. |
| Brass C360 | Copper-Zinc Alloy | Excellent machinability, good electrical conductivity, and good resistance to atmospheric corrosion. | Allows clean production of small precision features, threaded holes, fittings, and conductive components. | Electrical terminals, sensor housings, valve components, connectors, and decorative precision boxes. | Polishing Brushing Nickel plating | Brass is denser than aluminum. Chips should be managed carefully, and the selected alloy should match any applicable lead-restriction requirements. |
| Copper C110 | High-Conductivity Copper | Very high electrical and thermal conductivity with good ductility. | Ideal when a CNC box or internal component must transfer heat or carry electrical current efficiently. | Heat spreaders, busbar enclosures, power-electronics housings, and thermal management components. | Polishing Nickel plating Tin plating | Copper is soft and can produce burrs or a smeared surface if tools are dull. Clamping and chip evacuation require careful control. |
| POM (Acetal) | Engineering Thermoplastic | Low friction, low moisture absorption, good dimensional stability, and easy machinability. | Provides a lightweight, electrically insulating box for low-load applications requiring smooth movement or non-marring contact. | Insulating covers, sensor mounts, gear housings, prototype enclosures, and small mechanical assemblies. | Machined finish Polishing | Thermal expansion is higher than metals, so operating temperature and fit clearances must be considered during design. |
| PEEK | High-Performance Thermoplastic | High temperature capability, chemical resistance, wear resistance, and excellent electrical insulation. | Suitable for demanding CNC boxes that need low weight, chemical resistance, and stable performance at elevated temperatures. | Medical components, chemical equipment, aerospace-style housings, and high-temperature electrical insulation parts. | Machined finish Fine polishing | Material cost is high, and machining parameters must be controlled to avoid heat buildup, burrs, and dimensional variation. |
| ABS | General-Purpose Thermoplastic | Lightweight, impact resistant, electrically insulating, and easy to machine for prototypes and low-load parts. | Offers a practical option for economical CNC box prototypes and non-structural indoor enclosures. | Prototype electronics cases, instrument covers, display housings, and educational equipment enclosures. | Machined finish Painting | ABS has lower temperature and chemical resistance than engineering plastics such as PEEK. It is best suited to moderate service conditions. |