Brass is a family of copper–zinc alloys that combines outstanding machinability with good strength, corrosion resistance and electrical conductivity. It is an efficient choice for CNC‑machined parts that must be precise, durable and visually appealing without sacrificing manufacturability.
What Makes Brass Different as a CNC Material
Brass behaves very predictably under cutting, which is a major advantage when you need complex parts and repeatable quality across many batches. Tool life, chip control and surface finish are generally better than with most steels, and tight tolerances are easier to achieve than with many cast or formed materials.
Key benefits include:
- Fast, stable machining in milling and turning, especially in free‑cutting grades like C360.
- Built‑in corrosion resistance for plumbing, fluid handling and outdoor environments when the right alloy is selected.
- High electrical conductivity and good thermal behaviour for connectors, terminals and RF components.
- Low friction and good wear performance for moving parts such as bushings, bearings and small gears.
- Excellent response to polishing, brushing and plating for customer‑facing components.
Compared with aluminum, brass usually offers better wear resistance and a more substantial feel, at the cost of higher density. Compared with stainless steels, brass is generally easier and faster to machine and doesn’t always require additional coatings to resist corrosion.
Key Properties of Brass for Design
The table below provides indicative mechanical and physical properties for two common engineering brasses used in CNC machining. Use these values as a starting point for material comparison and early sizing, then confirm exact data from certificates for critical designs.
| Material | Density (g/cm³) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation at Break (%) | Hardness (Brinell) (HBW) | Fatigue Strength (MPa) |
|---|---|---|---|---|---|---|
| Brass C260 | ∼ 8.5 | 140 - 310 | 300 - 520 | 10 - 60 | 60 - 85 | 110 - 160 |
| Brass C360 | 8.45 - 8.55 | 150 - 300 | 340 - 470 | 10 - 30 | 80 - 110 | 80 - 120 |
Brass Alloys You Can Machine at Clarwe
Clarwe supports a range of brass alloys so you can align material choice with the mechanical, environmental and regulatory needs of each project. Instead of committing to a single generic “brass”, you can choose grades tuned for machinability, corrosion behaviour or strength.
Common Brass Grades
| Alloy | Main characteristics |
|---|---|
| Brass C260 cartridge brass | Balanced strength and corrosion resistance, very good cold formability |
| Brass C360 free‑cutting brass | Very high machinability, excellent chip control, good strength and surface finish. |
If you are not sure which grade to specify, you can share the application (medium, pressure, temperature, regulatory requirements) with Clarwe and we will recommend a brass alloy that fits.
Practical Design Guidelines for Brass CNC Parts
Brass’s machinability lets you push geometry further than many other metals, but some limits still help keep designs robust and economical. The guidelines below are a practical starting point for most CNC‑machined brass components.
| Design aspect | Recommended guideline for brass CNC parts |
|---|---|
| Minimum wall thickness (standard) | 0.8 mm |
| Minimum wall thickness (feasible) | 0.5 mm |
| Wall height‑to‑thickness ratio | Up to ~8:1 (e.g., 1.0 mm wall up to 8 mm tall) |
| Minimum hole diameter | ≥ 0.5–1.0 mm |
| Max depth for standard holes | ≤ 8× hole diameter (through), ≤ 4× diameter (blind) |
| Minimum fillet radius (critical) | 0.25–0.5 mm |
| Standard dimensional tolerance | ±0.05 mm |
| Tight tolerance range | ±0.02–0.025 mm |
| Standard surface roughness (Ra) | Milling: Ra 1.6–3.2 μm; Turning: Ra 0.8–1.6 μm |
| Fine surface finish (Ra) | Ra 0.4–0.8 μm |
| Maximum recommended roughness | Ra 3.2 μm for stressed mating surfaces |
If your design requires thinner walls, deeper holes or tighter tolerances than these general values, Clarwe can review the geometry and suggest adjustments or process changes.
Where CNC‑Machined Brass Performs Best
Brass is rarely the only possible material, but there are categories of parts where it consistently works very well. These examples are typical use cases; they are not a complete list of what brass can do:
Fluid and Plumbing Systems
Brass is a staple material for fluid handling because it resists many water‑based and non‑aggressive media and can be machined to reliable sealing features. Typical parts include:
- Valve bodies, stems and internal components
- Pipe, hose and compression fittings
- Flow regulators, couplings and water meter housings
Electrical and Electronic Hardware
For electrical and electronic assemblies, brass offers a helpful combination of conductivity, strength and machinability.
Examples:
- Terminals, pins and terminal blocks
- Battery posts and bus bars
- RF and communication connectors, shielding components and small enclosures
Mechanical and Industrial Components
When you need moving or load‑bearing parts that must still be easy to machine, brass is a strong candidate. Common uses include:
- Gears and small drive elements
- Bushings and bearings
- Instrument housings, sensor bodies and precision mechanical hardware
Finish Options for Brass CNC Components
Brass is a family of copper–zinc alloys that combines outstanding machinability Finishing choices affect how brass parts perform in service and how they appear in the final product. Clarwe can combine CNC machining with a range of finishes depending on your functional and cosmetic requirements.
Typical Brass Finishes
| Finish / treatment | Purpose |
|---|---|
| As‑machined, deburred | Functional surfaces with sharp edges removed; economical default. |
| Polished or brushed | Smoother, visually clean surface that reduces visible tool marks and enhances appearance. |
| Nickel or chrome plating | Improved wear and corrosion resistance and a bright, durable metallic finish. |
| Gold or silver plating | Higher conductivity and corrosion resistance with a premium cosmetic look for contacts/visible parts. |
| Clear lacquer / coating | Slows tarnishing while maintaining the natural brass colour. |
| Powder coating | Durable coloured coating with good impact and chemical resistance. |
For designs with tight fits or critical thread engagement, it is important to define whether tolerances apply before or after finishing, as some coatings and platings add measurable thickness.
Using Brass in Your Material Selection
Brass is a strong candidate if you recognise your project in one or more of these scenarios:
- You need precise machining with reliable sealing and thread quality in a wet or mildly corrosive environment.
- Your part is an electrical or electronic interface where conductivity, mechanical stability and cycling durability matter.
- The component will be visible to end‑users and must convey quality through weight, feel and finish.
- You require a combination of good wear behaviour and low friction in a compact mechanical design.
If another metal such as aluminum, stainless steel or bronze is also being considered, Clarwe can compare options and help you decide which material best supports performance, cost and supply objectives.
Once you have confirmed brass is suitable for your application and selected an alloy, you can share your CAD data with Clarwe to get manufacturability feedback and pricing for CNC machining.