50+ Metal Materials for CNC Machining
Metal Materials for CNC Machining: A Complete Guide
Metal materials are the foundation of precision CNC machining. Choosing the right metal determines how your part performs, how long it lasts, how much it costs, and how quickly it can be produced. At Baetro, we machine 50+ metal materials — from aluminum and stainless steel to titanium and brass — with instant quotes, free DFM feedback, and no minimum order quantity from our ISO-certified facility in Qingdao.
Engineers and buyers often underestimate how much material choice affects the success of a machined part. The wrong metal can turn a simple bracket into a nightmare of warping, tool wear, and blown budgets. The right metal makes the same part reliable, manufacturable, and cost-effective.
50+
Metal materials available
±0.001″
Standard machining tolerance
3-7 days
Standard lead time
MOQ 1
Prototype to production
Metal Materials Fundamentals
What Are Metal Materials?
Metal materials are solid substances characterized by metallic bonding, which gives them properties like electrical and thermal conductivity, ductility, strength, and a characteristic luster. In manufacturing, engineers classify metals by composition — pure metals like copper and titanium, or alloys like steel and brass that combine a base metal with other elements to improve specific properties.
For CNC machining, metal materials are typically supplied as bar stock, plate, sheet, or forgings. The CNC process removes material from these blanks using cutting tools guided by computer-controlled machine paths. The result is a precise part that matches the CAD model within specified tolerances.
Not all metals machine the same way. Some, like aluminum, cut easily and allow high speeds. Others, like titanium and stainless steel, require slower feeds, rigid setups, and specialized tooling. Understanding these differences is essential before specifying a material.
Metallic Bonding
Provides conductivity, ductility, and strength
Alloys vs. Pure Metals
Alloys combine elements to enhance specific properties
Bar Stock & Plate
Common raw forms for CNC machining
Machinability Varies
Aluminum cuts easily; titanium requires specialized tooling
50+ Metal Materials in Stock
From aluminum and stainless steel to titanium, brass, and copper.
Common Metal Families
Most Common Metal Materials for CNC Machining
The most common metal materials for CNC machining fall into six families: aluminum, stainless steel, carbon steel, brass, copper, and titanium. Each family contains multiple grades optimized for different mechanical, thermal, and chemical requirements.
Lightweight & machinable
Aluminum Alloys
Aluminum is the most widely machined metal material due to its low density, good strength-to-weight ratio, and excellent machinability. It is ideal for lightweight structural parts, heat sinks, electronic housings, and aerospace components.
- 6061-T6: General-purpose workhorse for brackets and frames.
- 7075-T6: High-strength aerospace alloy.
- 2024-T3: High fatigue resistance for aerospace structures.
- 5052-H32: Excellent formability for sheet metal.
Corrosion-resistant & strong
Stainless Steel
Stainless steel combines corrosion resistance, strength, and a clean appearance. It is specified for medical devices, food equipment, marine hardware, and any part exposed to moisture or chemicals.
- 304: Most common grade, excellent corrosion resistance.
- 316 / 316L: Superior chloride and marine corrosion resistance.
- 303: Free-machining grade for easier chip breaking.
- 17-4 PH: Precipitation-hardening with high strength.
High-performance materials
Titanium & Specialty Metals
Titanium delivers the best strength-to-weight ratio among common engineering metals, along with exceptional corrosion resistance and biocompatibility. Brass and copper offer excellent conductivity and machinability.
- Titanium Grade 2: Commercially pure, excellent corrosion resistance.
- Titanium Grade 5 (Ti-6Al-4V): High strength and heat resistance.
- Brass C360: Benchmark for machinability, ideal for fittings.
- Copper C110: Highest electrical and thermal conductivity.
Procurement confidence
Why Engineers Choose Baetro for Metal CNC Machining
Material selection is only half the battle. The other half is finding a supplier who can machine your metal parts accurately, quote them transparently, and deliver them on time.
50+ Metal Materials Available
From aluminum and steel to titanium and specialty alloys, we stock a wide range of grades to match your mechanical, environmental, and cost requirements.
Instant Online Quotes
Upload your STEP or IGES file, select material and finish, then receive pricing and lead time in under 60 seconds without waiting for manual sales follow-up.
No Minimum Order Quantity
Order 1 prototype or 100,000 production parts. Our process, quality standards, and inspection routines are the same regardless of quantity.
3–7 Day Standard Lead Times
Prototype metal parts ship in 3–7 days from order confirmation. Expedited options are available for urgent projects.
Free DFM Feedback on Every Quote
Our engineers review your CAD file, recommend the best metal material, and suggest design improvements that often reduce cost without affecting function.
ISO 9001 & AS9100 Certified
Quality systems ensure full traceability, CMM inspection, and complete documentation with every shipment — including material certifications and inspection reports.
Material library
Metal Materials We Machine
We machine 50+ metals with full material certifications and traceability available for every project.
Aluminum & Titanium
Aluminum Alloys: 6061-T6 general-purpose, excellent machinability, weldable; 7075-T6 high-strength aerospace-grade; 2024-T3 high fatigue resistance; 5052 corrosion-resistant and marine applications.
Learn more about aluminum CNC machining
Titanium: Grade 2 commercially pure for corrosion resistance; Grade 5 (Ti-6Al-4V) for high strength and heat resistance. Ideal for aerospace, medical, and marine applications.
Other Light Metals: Magnesium alloys for ultra-lightweight applications.
Steel, Brass & Copper
Stainless Steel: 304 general-purpose, corrosion-resistant, food-grade; 316 marine-grade, chemical-resistant, medical applications; 17-4 PH precipitation-hardened; 303 free-machining grade.
Learn more about stainless steel CNC machining
Carbon Steel: 1018 low-carbon for weldability; 1045 medium-carbon for strength; 12L14 free-machining for high-speed production; A36 structural steel.
Brass & Copper: Brass C360 (free-machining) for fittings and valves; Copper C110 for electrical and thermal conductivity.
Material
Stainless Steel
304, 316, 17-4 PH, and 303 grades for corrosion resistance and high strength.
Material
Titanium
Grade 2 and 5 for aerospace and medical applications requiring high strength-to-weight.
Material
Brass & Copper
C360 brass for machinability, C110 copper for electrical and thermal conductivity.
Post-processing
Surface Finishes for Metal CNC Parts
Surface finish affects appearance, corrosion resistance, wear, electrical conductivity, and cleanliness. The right finish depends on the metal material and the part’s end use.
| Finish | Compatible Metal Materials | Best For |
|---|---|---|
| As-machined | All metals | Functional parts, fastest turnaround |
| Anodizing | Aluminum | Corrosion protection, color, wear resistance |
| Powder coating | Aluminum, steel, stainless steel | UV durability, color, thick protective layer |
| Bead blasting | Aluminum, steel, titanium, brass | Uniform matte appearance, stress relief |
| Polishing | Aluminum, brass, copper, stainless steel | Mirror finish, decorative, cleanability |
| Plating | Steel, brass, copper | Conductivity, wear resistance, corrosion protection |
| Passivation | Stainless steel | Enhanced corrosion resistance, medical use |
| Black oxide | Steel | Mild corrosion resistance, appearance |
Choosing the right finish early prevents redesign later. For example, if your aluminum part needs a hard, colored surface, specify anodizing from the start. If your stainless steel part will be used in surgery, plan for passivation and electropolishing.
Engineering data
Metal Material Properties Comparison
Selecting the right metal material starts with understanding how key properties compare. The table below summarizes typical values for the most common CNC machining metals.
Typical Properties
| Metal Material | Density (g/cm³) | Tensile Strength (MPa) | Machinability | Corrosion Resistance | Relative Cost |
|---|---|---|---|---|---|
| Aluminum 6061 | 2.70 | 310 | Excellent | Good | $ |
| Aluminum 7075 | 2.81 | 572 | Good | Good | $$ |
| Stainless Steel 304 | 8.00 | 515 | Fair | Excellent | $$ |
| Stainless Steel 316 | 8.00 | 515 | Fair | Excellent | $$$ |
| Carbon Steel 1018 | 7.85 | 440 | Good | Poor | $ |
| Brass C360 | 8.49 | 338 | Excellent | Good | $$ |
| Copper C110 | 8.96 | 220 | Fair | Good | $$$ |
| Titanium Grade 5 | 4.43 | 950 | Poor | Excellent | $$$$ |
How to read: Density affects weight. Tensile strength indicates load capacity. Machinability directly impacts cycle time and cost. Corrosion resistance determines environmental durability.
How to Choose the Right Metal
- Density: Aluminum and titanium are lightweight; steel, stainless steel, brass, and copper are roughly three times denser.
- Tensile Strength: Titanium Grade 5 and aluminum 7075 lead; copper and brass are lower-strength.
- Machinability: Aluminum and brass machine quickly. Stainless steel and titanium slow production and increase tool wear.
- Corrosion Resistance: Stainless steel 316 and titanium excel in harsh environments. Carbon steel requires coatings for outdoor use.
Quality Assurance
Quality & Documentation for Metal Parts
Quality is not a final check. It is built into every stage of our metal machining process, from material verification to final dimensional inspection.
Engineering Partnership & Capability
- ISO 9001 certified quality management system
- AS9100 certified for aerospace quality standards
- Full material traceability from raw stock to finished part
- In-process inspection at multiple production stages
- CMM final inspection on Coordinate Measuring Machine equipment
- Surface roughness testing for finish validation
- First article inspection reports for production approval
- 100% inspection or AQL sampling per customer requirements
What You Receive with Every Shipment
Every order includes a comprehensive inspection report documenting key quality data for your metal CNC machined parts.
- Dimensional measurements against your drawing
- Material certification and traceability
- Surface finish verification when specified
- Pass/fail status for all critical dimensions
- Inspector signature and inspection date
Applications
Metal Material Applications by Industry
Different industries rely on different metal materials based on their unique performance demands.
Industry
Aerospace
Aerospace parts demand lightweight, high-strength metal materials. Aluminum 7075 and titanium Grade 5 dominate structural brackets, fasteners, and fittings with tight tolerances and full traceability.
Industry
Medical Devices
Medical device manufacturers specify stainless steel 316L and titanium Grade 23 for surgical instruments, implants, and diagnostic equipment. Biocompatibility, corrosion resistance, and precision finishing are critical.
Industry
Automotive
Automotive manufacturers use aluminum for engine brackets and housings, carbon steel for structural components, and stainless steel for exhaust and fuel system parts. Cost and weight drive most decisions.
Industry
Electronics
Electronics manufacturers favor aluminum for heat sinks and enclosures due to its light weight and thermal conductivity. Copper is used for bus bars and RF shields where electrical conductivity matters.
Industry
Industrial Equipment
Industrial machinery uses carbon steel, stainless steel, and brass for gears, shafts, valves, and fittings. Strength, wear resistance, and chemical compatibility guide material selection.
Industry
Marine
Marine environments attack most metals. Stainless steel 316, titanium, and certain brass alloys resist saltwater corrosion better than carbon steel or aluminum. Used for hardware, propeller shafts, and underwater housings.
Machining considerations
CNC Machining Considerations for Metal Materials
Each metal material behaves differently during CNC machining. Understanding these behaviors helps engineers design parts that are easier to manufacture and less expensive to produce.
Tool Wear & Cutting Speeds
Harder metal materials like stainless steel and titanium accelerate tool wear. They require slower cutting speeds, more rigid setups, and often specialized coatings like TiAlN. Softer metals like aluminum and brass allow much higher speeds and longer tool life.
- Aluminum: High speeds, long tool life
- Stainless steel: Moderate speeds, increased wear
- Titanium: Slow speeds, specialized tooling required
Workholding & Fixturing
Thin-walled parts, soft metals, and complex geometries need careful fixturing to prevent distortion. Aluminum and copper can deform under clamping pressure. Titanium and stainless steel may spring back during machining.
- Proper fixture design is essential for holding tight tolerances
- Soft jaws and vacuum fixtures for delicate parts
- Rigid setups for tough alloys
Heat Management & Chip Evacuation
Heat generated during machining must be controlled. Aluminum conducts heat well, so it is forgiving. Titanium and stainless steel trap heat at the cutting edge, requiring high-pressure coolant and optimized tool paths to prevent work hardening and tool failure.
- High-pressure coolant for stainless and titanium
- Sharp tools and proper feeds for chip control
- Copper requires careful chip evacuation to prevent wrapping
How to choose
How to Choose the Right Metal Material
Choosing between metal materials is rarely about finding the “best” metal. It is about finding the metal that meets all your requirements at the lowest total cost. Follow this decision framework.
Define Mechanical Requirements
What loads must the part handle? Tensile strength, fatigue resistance, hardness, or impact resistance? For heavily loaded parts, steel, stainless steel, or titanium may be required. For light-load brackets, aluminum is often sufficient.
Consider Environmental Exposure
Will the part see moisture, salt, chemicals, or high temperatures? Stainless steel 316 and titanium resist corrosion in marine and chemical environments. Carbon steel needs protection. Aluminum performs well outdoors with an anodized finish.
Evaluate Weight Constraints
Aerospace, robotics, automotive, and portable devices often prioritize low weight. Aluminum is the cost-effective lightweight choice. Titanium is the premium option when strength-to-weight is critical.
Factor in Machinability
Machinability affects both lead time and cost. A part that machines quickly in aluminum may take two to five times longer in stainless steel or titanium. If your design does not need the properties of a hard-to-machine metal, choosing a more machinable option saves money.
Account for Surface Finish
Different metals accept different finishes. Aluminum anodizes beautifully. Stainless steel passivates for medical use. Brass and copper polish to a mirror finish. Titanium can be anodized in colors. Match the material to the required finish early in design.
Balance Cost and Performance
Do not over-specify. The cheapest metal that meets all functional and environmental requirements is usually the right choice. Our engineers often recommend switching from titanium to aluminum or from stainless steel to carbon steel with plating, saving 30–60% without sacrificing performance.
Cost considerations
What Drives the Cost of CNC Machined Metal Parts
Material is only one part of CNC machining cost. Understanding all cost drivers helps you design parts that quote lower without sacrificing function.
- Material Grade and Form: Bar stock is usually the most economical. Premium grades like titanium Grade 5 or stainless steel 316 cost more than standard aluminum or carbon steel.
- Part Geometry and Machining Time: Complex parts with deep pockets, thin walls, and tight tolerances take longer to machine. Our free DFM feedback often identifies geometry changes that reduce machining time by 20% or more.
- Quantity: Setup costs are spread across parts, so higher quantities reduce per-part cost. However, Baetro has no minimum order quantity, so prototypes and low-volume orders remain economical.
- Surface Finish and Post-Processing: Each finishing step adds cost. A simple as-machined part is cheapest. Anodizing, powder coating, polishing, or plating add steps and handling.
- Lead Time: Standard lead time is 3–7 days. Expedited options are available when needed. Planning ahead keeps costs down.
FAQ
Frequently Asked Questions
Answers to common questions about metal materials, tolerances, lead times, DFM feedback, finishes, and quality control.
What are the most common metal materials for CNC machining?
The most common metal materials for CNC machining are aluminum alloys, stainless steel, carbon steel, brass, copper, and titanium. Aluminum 6061 is the most widely used due to its excellent machinability and low cost.
What is the easiest metal to machine?
Aluminum 6061 and brass C360 are the easiest common engineering metals to machine. They allow high cutting speeds, produce manageable chips, and cause minimal tool wear.
What is the strongest metal for CNC machining?
Titanium Grade 5 (Ti-6Al-4V) offers the best strength-to-weight ratio among common CNC machining metals. For absolute strength, hardened alloy steels and tool steels can exceed titanium but at much higher weight.
How do I choose between aluminum and stainless steel?
Choose aluminum when weight, cost, and machinability matter most. Choose stainless steel when corrosion resistance, strength, and appearance are more important. For marine or chemical environments, stainless steel 316 is usually the better choice.
How much does it cost to CNC machine metal parts?
Cost depends on the metal material, part geometry, tolerances, quantity, and finish. Aluminum is typically most economical. Titanium and Inconel are premium options. Upload your CAD file to get an instant quote and see exact pricing.
What metal is best for corrosion resistance?
Stainless steel 316 and titanium offer the best corrosion resistance among common CNC machining metals. Brass and copper also resist corrosion well in many environments.
Can metal parts be recycled?
Yes. Aluminum, steel, stainless steel, brass, copper, and titanium are all recyclable. CNC machining produces chips and scrap that can be reclaimed and reused.
What surface finishes are available for metal CNC parts?
Common finishes include as-machined, anodizing, powder coating, bead blasting, polishing, plating, passivation, and black oxide. The best finish depends on the metal material and application requirements.
Quote-ready manufacturing
Get Your Metal Parts Quote in 60 Seconds
Choosing the right metal material is one of the most important decisions in product development. The good news: you do not have to make it alone.
At Baetro, our engineers review every CAD file for manufacturability and recommend the best metal material for your application — whether you need the light weight of aluminum, the corrosion resistance of stainless steel, or the strength-to-weight performance of titanium. You get an instant quote, free DFM feedback, and no minimum order quantity.
Parts ship from our ISO-certified Qingdao facility in 3–7 days, with full inspection reports and material traceability. No minimums. No hidden fees. No waiting days for pricing.
Parts ship in 3–7 days. No minimum order quantity. ISO 9001 & AS9100 certified.
Not ready to upload a file? Contact our engineers to discuss your project, review material options, or get guidance on tolerance selection.