Selecting the right metal for your CNC machined component isn’t just about cost—it’s about finding the best fit for strength, durability, weight, and environmental conditions. At MDA Ltd, we work with customers across industries – from aerospace to automation – to help them choose materials that strike the perfect balance of performance and price.
Here’s a breakdown of three of the most commonly used metals in CNC machining: aluminum, carbon steel, and stainless steel.
🧪 1. Aluminum: Lightweight & Versatile
Popular Alloys: 6061, 7075, 2024
Density: ~2.7 g/cm³
Cost: Moderate
Machinability: Excellent
✅ Pros:
- Lightweight yet strong
- Highly machinable (faster cycle times, lower tool wear)
- Naturally corrosion-resistant
- Can be anodized for added protection and aesthetics
🚫 Cons:
- Lower wear resistance
- Lower strength compared to steel in structural applications
🔧 Best For:
- Aerospace parts (e.g. brackets, housings)
- Automotive and robotics
- Consumer electronics
- Lightweight fixtures and jigs
🔩 2. Carbon Steel: Strong, Affordable, and Durable
Popular Grades: 1018, 1045, 4140
Density: ~7.8 g/cm³
Cost: Low
Machinability: Good to Moderate
✅ Pros:
- High tensile strength
- Very cost-effective
- Easily heat-treated for added hardness
- Great for structural and load-bearing parts
🚫 Cons:
- Prone to corrosion unless coated or plated
- Heavier than aluminum (more weight per part)
🔧 Best For:
- Shafts, gears, frames, and tooling components
- Structural supports
- Agricultural and construction equipment
🛡️ 3. Stainless Steel: Strength with Corrosion Resistance
Popular Grades: 304, 316, 17-4 PH
Density: ~7.9 g/cm³
Cost: High
Machinability: Moderate to Difficult
✅ Pros:
- Excellent corrosion resistance
- Strong and wear-resistant
- Performs well in extreme temperatures
- Suitable for sterile or medical environments
🚫 Cons:
- Higher material and machining cost
- Work-hardens during machining (increased tool wear)
🔧 Best For:
- Medical devices and surgical tools
- Marine and food-grade components
- High-temperature or corrosive environments
- Aerospace and defense fasteners
🧠 How MDA Helps You Choose
When you send us a CAD or PDF file, we don’t just quote – we ask the right questions:
- What environment will the part operate in?
- Is weight or strength a priority?
- Does the part need post-finishing (plating, anodizing)?
- Are there regulatory or industry-specific material standards?
We’ll recommend the best material for your project, factoring in performance, cost, and supply chain availability.
🔚 Final Thoughts
Choosing the right metal for your CNC parts is critical to performance, cost-efficiency, and lead time. At MDA Ltd, we bring decades of machining expertise to help you make the right call – before the first chip is cut.