Precision Brass CNC Machining
Brass Material: CNC Machining Guide
Brass material gives engineers a rare combination of machinability, corrosion resistance, electrical conductivity, and an attractive finish. It is one of the easiest metals to machine, which makes it a go-to choice for precision connectors, valves, fittings, gears, and decorative hardware.
At Baetro, we machine custom brass parts from a range of copper-zinc alloys, with tolerances to ±0.001 inch and standard lead times of 3–7 days. Upload your CAD file for an instant brass CNC machining quote in under 60 seconds.
±0.001″
Machining tolerance
3–7 days
Standard lead time
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On every quote
MOQ 1
Prototype to production
Brass Material Guide
What Is Brass?
Brass is an alloy made primarily of copper and zinc. The zinc content typically ranges from 5% to 45%, with copper making up the balance. Small additions of lead, tin, aluminum, manganese, iron, or silicon create specialized grades with different color, strength, machinability, and corrosion characteristics.
This versatility makes brass one of the most widely used engineering alloys. Its warm gold-like appearance and ease of machining have made it a staple in plumbing, electrical, automotive, and decorative applications for centuries.
Copper-Zinc Alloy
Primary composition — copper with 5–45% zinc
Wide Composition Range
Alpha, alpha-beta, and beta phases determine properties
Alloying Additions
Lead improves machinability; tin enhances corrosion resistance
Color & Finish
Ranges from golden-yellow to reddish-gold based on zinc content
One of the Most Machinable Metals
Brass produces short, brittle chips and excellent surface finishes — ideal for high-speed CNC turning and milling.
Brass Alloy Guide
Common Brass Alloys for CNC Machining
Choosing the right brass material means balancing machinability, strength, corrosion resistance, regulatory requirements, and cost.
Free-Cutting
C36000 Free-Cutting Brass
C36000 is the most machinable brass alloy and the default choice for precision machined parts. It contains approximately 2–3% lead, which creates excellent chip control and allows high-speed turning, drilling, and threading.
- Best for: high-volume production, intricate turned parts
- Key properties: excellent machinability, good surface finish
- Applications: fasteners, fittings, connectors, valve components
Cartridge Brass
C26000 Cartridge Brass
C26000 contains about 70% copper and 30% zinc. It is lead-free, ductile, and formable, with good corrosion resistance and slightly higher electrical conductivity than C36000.
- Best for: electrical contacts, stamped and formed parts
- Key properties: lead-free, ductile, good conductivity
- Applications: terminals, connectors, formed components
Yellow Brass
C27400 Yellow Brass
C27400 offers a practical balance of strength, ductility, machinability, and economy. It machines well and can be used for general hardware, fittings, and decorative parts where C36000 is not required.
- Best for: general-purpose hardware and fittings
- Key properties: balanced strength and machinability
- Applications: cost-sensitive machined parts, decorative hardware
Muntz Metal
C28000 Muntz Metal
C28000 has a higher zinc content, which increases strength but reduces ductility compared to C26000. It is often used in architectural and marine applications where a combination of strength and corrosion resistance is needed.
- Best for: structural hardware, architectural trim
- Key properties: higher strength, marine-grade
- Applications: marine components, structural fittings
Naval Brass
C46400 Naval Brass
C46400 naval brass adds about 0.8% tin to improve seawater corrosion resistance. It is harder and less machinable than C36000 but is the standard choice for marine hardware exposed to saltwater.
- Best for: marine hardware, saltwater valves
- Key properties: seawater corrosion resistance, high strength
- Applications: pumps, propeller shafts, corrosion-critical components
Get Started
Need Brass Parts?
Upload your CAD file for an instant quote on precision brass machining — free DFM feedback, no minimums, fast lead times.
- Free DFM review on every design
- 3–7 day standard lead time
- ±0.001" tolerance capability
CNC Machining Processes
CNC Machining Processes for Brass
Brass works well across several CNC processes. The right choice depends on part geometry, tolerance requirements, and production volume.
CNC Turning
CNC turning services are ideal for brass shafts, pins, bushings, fittings, and threaded components. Brass's excellent machinability allows high spindle speeds and fine surface finishes, often eliminating the need for secondary polishing.
CNC Milling
CNC milling handles prismatic brass parts such as housings, brackets, manifolds, and complex mechanical hardware. Sharp carbide tools and proper chip evacuation produce clean edges and accurate dimensions.
Swiss Machining
For small-diameter precision parts, Swiss machining delivers tight tolerances and excellent surface finishes in brass. This process is common for medical connectors, watch components, and small electronic hardware.
Drilling & Tapping
Brass drills and taps cleanly, making it ideal for threaded fittings, fluid ports, and mounting holes. Proper speeds and feeds prevent chip packing and ensure accurate threads.
Why Brass Excels in CNC
Brass offers exceptional machinability across all CNC processes. Its short, brittle chips prevent tool clogging, while its natural lubricity reduces tool wear and improves surface finish. Brass parts often require less deburring and post-processing than steel or aluminum equivalents.
Get Started with Brass Machining
Upload your CAD file for an instant quote on precision brass parts — free DFM feedback, no minimums, and fast lead times. Our engineers will help you select the optimal alloy and process for your application.
Material Properties
Key Brass Material Properties
Understanding brass material properties helps engineers match the right alloy to the job. Properties vary by grade, but the ranges below apply to common engineering brasses.
Mechanical Properties
| Property | Typical Range |
|---|---|
| Tensile strength | 300–380 MPa (standard leaded brass) |
| Hardness | 80–100 HB (Brinell) |
| Elongation | 10–25% |
| Machinability rating | Excellent; C36000 is the benchmark (100) |
Values vary by alloy, temper, and supplier. Always confirm properties against the material certificate for critical applications.
Machinability & Corrosion Resistance
Machinability
Brass is widely regarded as the easiest metal to machine. C36000 free-cutting brass is the industry machinability benchmark, rated 100. The lead content in C36000 acts as an internal lubricant, producing fine broken chips and smooth surface finishes. Brass allows cutting speeds of 400–600 SFM and often higher with carbide tools.
Corrosion Resistance
Brass resists corrosion in many atmospheric and freshwater environments. However, standard brasses can suffer dezincification in aggressive conditions, particularly saltwater. Naval brass (C46400) contains tin for superior seawater resistance, making it the preferred choice for marine hardware.
Alloy
C36000
Benchmark machinability (100). Excellent for high-speed turning and intricate features.
Alloy
C46400 Naval Brass
Tin‑added for superior seawater corrosion resistance. Preferred for marine hardware.
Alloy
C26000 Cartridge Brass
Lead‑free, ductile, good conductivity. Ideal for formed parts and electrical contacts.
Alloy
C69300 Eco‑Brass
Silicon‑based lead‑free alternative. Matches machinability of C36000 for regulated applications.
Material Comparison
Brass vs Bronze vs Copper: Which Metal to Choose
Engineers often compare brass, bronze, and copper when selecting a non-ferrous metal. Each has distinct strengths.
| Property | Brass (C36000) | Bronze (C93200) | Copper (C11000) |
|---|---|---|---|
| Machinability | Excellent (100) | Moderate (~50) | Poor–Moderate (~20) |
| Electrical conductivity | ~26% IACS | ~15% IACS | ~100% IACS |
| Corrosion resistance | Good | Excellent, especially marine | Good, but oxidizes |
| Wear resistance | Moderate | Excellent | Low |
| Cost | Lowest | Higher | Highest |
| Best for | Precision fittings, connectors, hardware | Bearings, bushings, marine parts | Busbars, heat sinks, electrical parts |
Choose brass for fast, cost-efficient machining of precision parts. Choose bronze for bearings, bushings, and marine components where wear and corrosion resistance matter. Choose copper when electrical or thermal conductivity is the top priority. For a deeper look at conductivity differences, see our copper vs brass vs bronze electrical conductivity guide.
Regulatory Compliance
Lead‑Free and Eco‑Brass Options
Regulations such as RoHS, REACH, NSF/ANSI 61, and the Safe Drinking Water Act restrict lead content in many applications. Lead‑free options include C26000, C34000, and C69300 Eco‑Brass. These grades use silicon, bismuth, or other additives to maintain machinability without lead.
Brass Alloy Comparison
| Alloy | Common Name | Lead‑Free | Best For | Machinability |
|---|---|---|---|---|
| C36000 | Free‑cutting brass | No | Fasteners, fittings, connectors | Excellent (100) |
| C26000 | Cartridge brass | Yes | Electrical contacts, formed parts | Good |
| C27400 | Yellow brass | Yes | General hardware, fittings | Good |
| C28000 | Muntz metal | Yes | Architectural, marine structural | Fair–Good |
| C46400 | Naval brass | Yes | Marine hardware, saltwater parts | Good |
| C69300 | Eco‑Brass | Yes | Plumbing, medical, regulated parts | Good |
Best for: Medical devices, plumbing fittings, potable‑water components, and electronics sold in regulated markets.
Choose the Right Alloy for Your Application
- Standard leaded brass (C36000): highest machinability — ideal for high‑volume precision parts where lead restrictions do not apply.
- Lead‑free options (C26000, C27400, C28000, C46400, C69300): comply with RoHS, REACH, NSF/ANSI 61, and other global regulations.
- Eco‑Brass (C69300): silicon‑based alternative that matches the machinability of leaded brass — preferred for potable water and medical applications.
- Engineering support: upload your CAD file and our engineers will recommend the optimal brass alloy for your regulatory and performance requirements.
Quality Assurance
Brass Machining Tolerances and Quality
Brass can hold tight tolerances when machined with the right tooling, workholding, and process control.
Precision & Surface Finish
- Standard tolerance: ±0.001 inch (±0.025 mm) for most features
- Precision tolerance: ±0.0005 inch (±0.0127 mm) achievable on critical features
- Surface finish: naturally smooth as-machined; polishing, plating, or passivation available
- Inspection: every part inspected on CMM equipment with dimensional reports
- Process control: documented tooling, workholding, and machining parameters
What You Receive with Every Shipment
Every brass order ships from our ISO 9001 certified Qingdao facility with documented process controls.
- Material certificates with full traceability
- Dimensional inspection reports from CMM equipment
- Surface finish verification when specified
- AS9100 certification available for aerospace and defense
- Pass/fail status for all critical dimensions
Brass Applications
Applications of CNC Machined Brass
Brass appears across many industries because it combines machinability, durability, and an attractive finish.
Electrical
Connectors & Terminals
Brass offers moderate electrical conductivity with excellent strength and spring characteristics. C26000 is commonly used for contacts, terminals, pins, and sockets.
Plumbing
Valves, Fittings & Plumbing
C36000 and lead-free brass grades are widely used for valves, pipe fittings, manifolds, and fluid-control components. Lead-free grades are required for potable-water applications.
Marine
Marine Hardware
Naval brass (C46400) resists saltwater corrosion and is used for propeller shafts, pump components, cleats, and marine fasteners.
Automotive
Automotive Components
Brass fittings, sensors, connectors, and bushings appear throughout automotive fuel, cooling, and electrical systems.
Architectural
Decorative & Architectural Hardware
Brass's warm color and ability to take a high polish make it popular for door hardware, handrails, lighting fixtures, and instrument panels.
Medical
Medical & Instrumentation
Lead-free brass grades are used in surgical instruments, diagnostic equipment, and analytical instruments where machinability and regulatory compliance are both required.
Alloy Selection Guide
Brass Material Selection Guide
Selecting the right brass material means matching alloy characteristics to application requirements.
Choose C36000 When…
- Machinability and cycle time are the top priorities.
- The part has intricate features, threads, or tight tolerances.
- Lead content is acceptable for the application.
- You need a bright, attractive as-machined finish.
Choose C26000 When…
- The application requires a lead-free alloy.
- Electrical conductivity is important.
- The part will be formed, stamped, or crimped.
Choose C46400 or Lead-Free Brass When…
- C46400: exposed to saltwater or marine environments; corrosion resistance is critical; pumps, valves, propeller hardware.
- Lead-Free (C69300, C26000, etc.): contacts drinking water, food, or human tissue; meets RoHS/REACH; medical, plumbing, consumer electronics.
Surface Engineering
Surface Finishes for Brass Parts
Surface treatments improve appearance, corrosion resistance, wear properties, and electrical performance. The right finish depends on the operating environment, aesthetic requirements, and functional needs of the part.
Polishing & Buffing
Creates a bright, mirror-like appearance for decorative hardware and consumer products. Polishing removes surface imperfections and enhances brass's natural warm gold color.
Plating (Nickel, Chrome, Gold, Silver)
Improves wear resistance, conductivity, and appearance. Nickel and chrome plating provide durability; gold and silver plating are used for electrical contacts and premium finishes. Our plating services apply consistent coatings in-house.
Passivation & Anti-Tarnish Coating
Slows oxidation and discoloration, extending the service life of exposed brass components. Anti-tarnish coatings are especially valuable for decorative and marine applications where appearance retention is critical.
Bead Blasting
Produces a uniform matte or satin finish that hides minor machining marks. Bead blasting creates an even, textured surface ideal for industrial components and preparation for coating.
As-Machined (Natural Brass)
Brass machines to a naturally smooth, attractive finish. For many functional parts, no additional treatment is required. The natural surface offers good corrosion resistance and a clean appearance without added cost.
Choose the Right Finish
Consider the operating environment (indoor, outdoor, marine), aesthetic requirements (bright, matte, textured), and functional needs (wear resistance, conductivity, corrosion protection). Our engineers recommend finishes during DFM review based on your specific application.
Physical Properties
Physical Properties of Brass
Key physical characteristics of brass that influence material selection, machining, and application performance.
- Density: ~8.3–8.7 g/cm³ — heavier than aluminum but lighter than steel; contributes to solid feel in hardware and fittings.
- Melting point: ~900–940°C — varies with zinc content; higher zinc lowers the melting range.
- Thermal conductivity: ~110–180 W/m·K (alloy‑dependent) — good heat dissipation for valves, fittings, and heat exchanger components.
- Electrical conductivity: ~25–30% IACS for standard brasses; advanced high‑conductivity brasses can exceed 60% IACS — suitable for electrical terminals and connectors.
- Color: Gold-yellow to reddish-brown, depending on copper content — higher copper produces a redder hue; the warm appearance makes brass popular for decorative and architectural hardware.
FAQ
Frequently Asked Questions About Brass Machining
Answers to common questions about brass material properties, alloys, machinability, corrosion resistance, finishes, and quality control.
Is brass easy to machine?
Yes. Brass is one of the easiest metals to machine. C36000 free-cutting brass is the machinability benchmark, producing clean chips and excellent surface finishes at high cutting speeds.
What is the most machinable brass alloy?
C36000 free-cutting brass is the most machinable, rated 100 on the machinability index. It machines roughly 25–40% faster than C26000 brass.
What is C360 brass used for?
C360 brass is used for precision fasteners, fittings, connectors, valve bodies, and hardware where machinability and surface finish are critical.
Is brass corrosion resistant?
Brass resists corrosion in many environments. Standard brasses perform well in freshwater and atmospheric conditions. Naval brass (C46400) offers superior resistance in saltwater and marine applications.
What are common brass surface finishes?
Common finishes include polishing, nickel plating, chrome plating, gold plating, passivation, anti-tarnish coating, and bead blasting.
Can brass be used for medical or food applications?
Leaded brass is generally unsuitable. Lead-free grades such as C26000 or C69300 Eco-Brass are used for medical, plumbing, and food-contact parts subject to RoHS and NSF requirements.
How fast can Baetro machine brass parts?
Baetro ships standard brass machined parts in 3–7 days with no minimum order and instant quotes in under 60 seconds.
Brass CNC Services
Start Your Brass Project with Baetro
Understanding brass material properties is the first step toward a successful part. Whether you need the machinability of C36000, the corrosion resistance of naval brass, or a lead‑free grade for a regulated application, Baetro can machine and finish your brass parts with precision and speed.
Upload your CAD file today for an instant quote in under 60 seconds — with free DFM feedback, transparent pricing, and no minimum order quantity. Our engineers will help you select the optimal alloy, tolerances, and finish for your specific application.
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 alloy options, or get guidance on tolerance and finish selection.