Selecting the optimal material is a critical decision that balances performance, aesthetics, and budget. At REBAN, we eliminate the complexity of material sourcing by providing a curated selection of over 50+ industrial-grade metals and plastics, all backed by certified mill test reports.
CNC Machining Material Selection Guide
Overview
To manufacture high-performance components, selecting the correct substrate is the first step in Design for Manufacturing (DfM). At REBAN, we leverage local material clusters to provide over 50+ certified metal and plastic grades. Whether you require high strength-to-weight ratios or specific thermal conductivity, this guide simplifies the selection process for your next CNC project.
1. Aluminium Alloys
Aluminium is the most frequently machined material at REBAN due to its excellent machinability, high strength-to-weight ratio, and superior anodizing capabilities.
- Aluminium 6061-T6: The “General Purpose” grade. Excellent weldability and structural strength.
- Aluminium 7075-T6: Aerospace grade. Offers strength comparable to many steels but at one-third the weight.
- Aluminium 6063: Optimized for complex extrusions and superior surface finishes (ideal for consumer electronics).
Mechanical Properties Comparison (Aluminium)
| Alloy Grade | Yield Strength (MPa) | Hardness (HB) | Machinability Index | Thermal Conductivity (W/m-K) | Anodizing Quality |
|---|---|---|---|---|---|
| 6061-T6 | 276 | 95 | Excellent (50%) | 167 | Excellent (Structural) |
| 7075-T6 | 503 | 150 | Good (80%) | 130 | Good (Matte Finish) |
| 2024-T3 | 345 | 120 | Fair (70%) | 121 | Poor (High Copper) |
| 5083-H111 | 145 | 75 | Moderate (35%) | 120 | Excellent (Marine Grade) |
| 6082-T6 | 260 | 95 | Excellent (50%) | 180 | Very Good |
| Mic-6 (Cast) | 105 | 65 | Superior (Easy) | 142 | Fair (Functional) |
2. Stainless Steel Grades
Ideal for environments requiring high corrosion resistance and hygiene.
- SS304/304L: The standard stainless steel. High corrosion resistance and excellent formability.
- SS316/316L: Marine grade. Addition of Molybdenum prevents pitting in chloride environments.
- SS17-4PH: Precipitation-hardened. Combines high strength with significant corrosion resistance; ideal for aerospace fasteners.
Mechanical Properties Comparison (Stainless Steel)
| Grade | Tensile Strength (MPa) | Hardness (HB) | Weldability | Magnetic | REBAN Engineering Insight |
|---|---|---|---|---|---|
| SUS 303 | 515 | ≤ 262 | Poor | No | The most machinable austenitic grade. Contains Sulfur for high-speed turning. |
| SUS 304 | 505 | ≤ 201 | Excellent | No | Global standard for general corrosion resistance; widely used in medical & food. |
| SUS 316L | 485 | ≤ 217 | Excellent | No | Lower carbon prevents sensitization. Best for marine and surgical environments. |
| SUS 420 | ≥ 635 | 48 – 52 HRC | Fair | Yes | Martensitic steel. Heat-treatable for extreme hardness; ideal for blades and molds. |
| 17-4 PH | 1030 | 331 (H900) | Good | Yes | Precipitation hardening. High strength and moderate corrosion resistance. |
| SUS 316Ti | 520 | ≤ 217 | Good | No | Titanium-stabilized. Superior for high-temperature chemical processing. |
3. Steel & Tool Steel
For heavy industrial machinery, automotive parts, and high-wear applications.
- Carbon Steel (1018 / 1045): Economical and easy to machine; often case-hardened for better wear.
- Alloy Steel (4140 / 4340): High toughness and fatigue strength. Suitable for axles and high-stress crankshafts.
- Tool Steel (D2 / H13 / P20): Extremely high hardness and heat resistance; used primarily for molding and cutting tools.
4. Engineering Plastics (Rigid & High-Performance)
CNC machining plastics is a core competency at REBAN, providing cost-effective alternatives to metal for insulation and low-weight requirements.
- POM (Delrin/Acetal): High stiffness, low friction, and excellent dimensional stability. The “Plastic of choice” for mechanical gears.
- PEEK: High-temperature resistance (up to 250°C) and excellent chemical resistance. Used for medical implants and oil & gas.
- PC (Polycarbonate): Transparent and virtually unbreakable. Used for protective covers and optical components.
- PTFE (Teflon): Exceptional chemical inertness and lowest coefficient of friction.
Plastic Performance Chart
| Material | Density (g/cm³) | Flexural Modulus (GPa) | Max Operating Temp (°C) | Machinability | REBAN Engineering Insight |
|---|---|---|---|---|---|
| POM (Delrin) | 1.41 | 2.6 | 90 – 105 | Superior | High stiffness and low friction. Ideal for gears, bearings, and precision manifold blocks. |
| PEEK | 1.32 | 4.1 | 250 – 260 | Moderate | Exceptional chemical resistance. The gold standard for aerospace and medical implants. |
| PC (Polycarbonate) | 1.20 | 2.3 | 115 – 130 | Excellent | Optical clarity and extreme impact resistance. Can be vapor polished for transparency. |
| PTFE (Teflon) | 2.15 | 0.5 | 260 | Good (Soft) | Lowest coefficient of friction. Best for high-temp seals and non-stick industrial parts. |
| Nylon 66 (PA66) | 1.14 | 2.8 | 80 – 120 | Good | High mechanical strength and wear resistance. Note: Absorbs moisture over time. |
| ABS | 1.05 | 2.1 | 70 – 85 | Superior | Most cost-effective for functional prototypes. Excellent for painting and plating. |
| ULTEM (PEI) | 1.27 | 3.3 | 170 – 200 | Fair | High dielectric strength and flame resistance. Often used in electrical connectors. |
5. Specialty Metals: Titanium, Copper & Brass
- Titanium Grade 5 (Ti-6Al-4V): The gold standard for high-performance weight reduction.
- Copper (C11000): Highest electrical and thermal conductivity. Essential for EV busbars and heat sinks.
- Brass (C360/H59): Excellent machinability and natural corrosion resistance. Used for decorative hardware and fluid fittings.
Engineering the Machined Foundation
At REBAN, CNC materials are the precision-engineered bedrock of your product. We master the critical variables of machinability, internal stress, and thermal stability to achieve micron-level tolerances. By merging cutting-edge metallurgy with high-speed spindle precision, we ensure your designs perform under extreme loads—from aerospace turbine components to high-frequency semiconductor housings.
Our Machining Integrity Standards
Metallurgical Verification: Every billet and plate undergoes ultrasonic testing for internal voids and grain uniformity to ensure predictable material behavior.
Specialized Alloy Portfolio: We stock high-performance materials including Inconel/Hastelloy superalloys, medical-grade Titanium, and engineered plastics (PEEK/Ultem).
Geometric Repeatability: Real-time metrology and tool-wear compensation ensure your 10,000th unit is identical to the first.