Metal Materials for CNC Machining: Material Selection Guide
Each material has its characteristics and processing technology. The following common material introduction can help you understand how to choose the material that suits your project. If you need help, please contact our engineering staff, they will give you a detailed answer.
Lightweight, Cost-Effective Engineering Metal
Most widely used CNC metal (30% the weight of steel), excellent machinability, cost-effective
6061-T6
General purpose, good strength, weldable (310 MPa)
7075-T6
High strength aerospace grade (572 MPa)
5083
Marine-grade, superior corrosion resistance
2024
Aircraft structures, high fatigue resistance
- Lightweight design
- Easy to machine
- Can be anodized
- Excellent thermal management
Applications
Prototyping, weight-reduction projects, high-volume production
Stainless Steel
Durable, Corrosion-Resistant Alloys.
Superior corrosion resistance (10.5%+ chromium), high strength, excellent durability
304
Most common, excellent corrosion resistance, food-grade
316/316L
Marine grade, superior corrosion resistance, medical-grade
303
Free-machining" grade, best machinability (515 MPa)
17-4 PH
Precipitation hardening, very high strength (1,310 MPa)
- Excellent corrosion resistance
- High strength & durability
- Easy to sterilize
- Wide temp range (-200°C to +800°C)
- Aesthetic appeal
Applications
Corrosive environments, medical/food-grade requirements, high-strength structural parts
Steel Alloys
Maximum Strength & Hardness
Highest strength, excellent wear resistance, heat-treatable for enhanced properties
1018 Mild Steel
General purpose, good machinability, weldable
4140 Alloy Steel
High strength, good toughness, versatile
4340 Alloy Steel
Superior strength, aerospace applications
D2 Tool Steel
High wear resistance, cutting tools, dies
- Highest strength-to-cost ratio
- Heat-treatable
- Excellent wear resistance
- Wide availability
Applications
High-strength structural parts, wear-resistant components, tooling
Brass Alloys
Decorative, Machinable Copper-Zinc Alloy
Best machinability of all metals, low friction, corrosion-resistant, aesthetic appeal
C360 (Free-Cutting Brass)
Best machinability (30% lead content)
C260 (Cartridge Brass)
Good formability, plumbing applications
C464 (Naval Brass)
Corrosion-resistant, marine applications
- Easiest metal to machine
- Low friction
- Antimicrobial properties
- Aesthetically appealing
- Good electrical conductivity
Applications
High-volume production, decorative parts, low-friction applications, Plumbing
Copper
Superior Electrical & Thermal Conductivity
Best electrical/thermal conductivity of all common metals, highly ductile, antimicrobial
C101 (Oxygen-Free Copper)
Highest conductivity, electrical applications
C110 (Electrolytic Tough Pitch)
General purpose, good balance
C145 (Tellurium Copper)
Free-machining, high-speed applications
- Easiest metal to machine
- Low friction
- Antimicrobial properties
- Aesthetically appealing
- Good electrical conductivity
Applications
High-volume production, decorative parts, low-friction applications, Plumbing
Titanium Alloys
High-Performance Engineering Metal
Best strength-to-weight ratio, biocompatible, extreme corrosion resistance
Grade 2 (CP Titanium)
Excellent corrosion resistance, biocompatible (345 MPa)
Grade 5 (Ti-6Al-4V)
Most common, aerospace standard (895 MPa)
Grade 23 (Ti-6Al-4V ELI)
Medical-grade, ultra-pure for implants
- Exceptional strength-to-weight
- Biocompatible
- Corrosion-proof
- Temp resistant (-200°C to +600°C)
- Non-magnetic
Applications
Weight-critical aerospace parts, medical implants, extreme environments
Nickel Alloys
Extreme Temperature & Corrosion
Exceptional high-temperature strength, extreme corrosion resistance, superalloy performance
Inconel 625
High-temp corrosion resistance (827 MPa)
Inconel 718
Aerospace turbine blades, very high strength
Monel 400
Nickel-copper alloy, marine applications
- Extreme temperature resistance
- Excellent corrosion/oxidation resistance
- High strength at elevated temps
- Resistant to creep
Applications
Extreme-environment applications (high heat, corrosive chemicals)
Zinc Alloys
Die-Casting & Plating Material
Low melting point, good castability, corrosion protection (galvanizing)
Zinc Alloys
- Low melting point
- Good strength-to-weight ratio
- Self-lubricating
- Excellent for die-casting
Applications
Die-cast components, protective coatings
Magnesium Alloys
Ultra-Lightweight Structural Metal
Lightest structural metal (35% lighter than aluminum), excellent machinability
Magnesium Alloys
- Lightest metal option
- Superior vibration damping
- Excellent EMI shielding
- Good machinability
Applications
Extreme weight reduction applications
FAQs
Aluminum 6061 is the most cost-effective metal overall, offering excellent machinability, good mechanical properties, and low material cost. It machines 3-5x faster than steel, significantly reducing production costs.
Yes, but it's challenging and expensive. Hardened steel (above 45 HRC) requires specialized carbide or ceramic tooling, slow cutting speeds, and expert programming. It's often more economical to machine parts in annealed state, then heat-treat afterward.
Aluminum and brass offer the best dimensional stability and ease of achieving tight tolerances (±0.005mm). Steel and stainless can also achieve tight tolerances but require more careful process control.
Choose aluminum for: weight reduction, high-volume production, thermal management, cost savings. Choose stainless steel for: corrosion resistance, high strength, medical/food applications, aesthetic durability.
316 contains 2-3% molybdenum, giving it superior corrosion resistance, especially against chlorides and saltwater. Use 304 for general applications; use 316 for marine, chemical, or medical applications.
Titanium machining is expensive (5-10x cost of aluminum) due to slow cutting speeds, high tool wear, and material cost. It's economical only when its unique properties (strength-to-weight, biocompatibility, corrosion resistance) are essential.
304/316 stainless steel, aluminum (food-grade), brass (lead-free grades), and copper are FDA-approved for food contact. Always verify specific grade compliance.
Material machinability directly impacts production time and cost. Easy-to-machine metals (aluminum, brass) can reduce costs by 50-70% compared to difficult materials (titanium, Inconel) due to faster cutting speeds and lower tool wear.