LK Tools CNC machining of brass parts

Brass is an alloy composed of copper and zinc in varying proportions, crafted to meet specific mechanical and physical properties. Its unique attributes have made brass a favored material for CNC machining, producing a variety of components ranging from automotive and medical equipment to aircraft. Brass items are a common part of our daily lives, found in furniture, door handles, cookware, wires, musical instruments, automotive parts, and beyond.

In brass alloys, the proportion of copper (55% to 95%) typically exceeds that of zinc (5% to 45%). Lead is also added in small amounts (less than 2%) to enhance the machinability of brass, facilitating processes like cutting, milling, and turning.

In this article from LK Tools, we will overview the various types of brass, the characteristics, advantages, and applications of CNC machining brass parts.

Common Brass Grades in CNC Machining:

Brass grades are categorized based on the content of zinc, copper, lead, and iron. These proportions vary in physical and mechanical properties, making them suitable for a wide range of applications. Among the various types, four grades – C-360, C-260, C-280, and C-464 – are most commonly used in CNC manufacturing.

C-360 Brass:
Recognized for its excellent machinability and strength, C-360 is the best type among other brasses. Its composition consists of approximately 35% zinc, along with lead and iron around 3%, and the remainder is copper. It is primarily used in automatic screws, musical instruments, hardware, and medical equipment parts. However, due to its lead content, it has some drawbacks, such as occasional surface finish cracks and sensitivity to acids.

C-260 Brass:
This extra zinc-copper formulation contains a small amount of lead and iron. It has about 20% zinc and 1% lead and iron. Historically used in ammunition cartridges, manufacturers also colloquially call it cartridge brass. With good thermal conductivity, corrosion resistance, and tensile strength, this brass is suitable for many applications, including power sockets, costume jewelry, buttons, pressure conveyance systems, and watch parts.

C-280 Brass:
It's a robust grade of brass initially developed for ship hull linings, with a copper-to-zinc ratio of 3:2. Its high strength and excellent corrosion resistance make it very effective for producing marine and architectural components.

C-464 Brass:
This brass is specially used for producing naval ship parts in high-humidity environments. Its unique composition provides extraordinary corrosion resistance and high strength. It contains 59% copper, 40% zinc, 1% tin, and very little lead. Of course, strength makes CNC machining more challenging, but we at LK Tools have the specialized tools and expert engineers to perfect it.

Advantages:

  1. Ease of Machining:
    Brass is one of the easiest alloys to machine with CNC. C-360 has a 100% machining rating. Due to the high speed at which brass can be machined and the improved material removal rate, its excellent machinability can significantly reduce processing times. Typically, when using brass rods as workpieces on CNC machines, there is no damage to the machining tools.

  2. Diverse Attributes:
    Brass comes in different grades, each with varying attributes like hardness, elasticity, and strength. By mixing different amounts of copper, zinc, lead, and iron, achieving the desired performance is easily attainable. Hence, choosing the right brass grade for the part to be manufactured is straightforward.

  3. Precision Machining:
    Brass possesses characteristics that aid in the dimensional stability of CNC machined parts, including a low coefficient of deformation, high machinability, and excellent impact resistance. Therefore, brass CNC machining is an effective method for manufacturing products with stringent tolerances.

  4. Safe Processing:
    Unlike other materials such as plastics, brass does not produce toxic byproducts during CNC machining. Thus, it is a non-sparking material, making the processing entirely safe.

  5. Compatibility with Machining Tools:
    The preferred CNC machining of brass parts is rod-type workpieces. However, brass is compatible with all types of tools, whether for cutting, milling, turning, drilling, or any other operation required for production. This attribute of brass contributes to frictionless machining and improved processing efficiency.

  6. Recyclability:
    Brass CNC machined products and parts are fully recyclable. Hence, when the product lifecycle is complete, brass can be reused after recycling. Another excellent feature is the ability to separate zinc and copper for reuse.

  7. Suitable for High Humidity and Temperatures:
    Since they do not melt rapidly at high temperatures (withstanding at least 800 C), parts produced by CNC machining can withstand thermal challenges, making them ideal for applications where temperature poses a challenge to functionality. Additionally, they can resist rusting in high-humidity conditions without losing their performance.

  8. Aesthetic Advantage:
    Brass shines brightly and comes in a variety of colors, from red to yellow. This is because the content of zinc determines the color. Thus, it doesn't require additional coating compared to other materials like steel and plastic.

Disadvantages:

  • Black oxidation reactions are a risk with brass, necessitating regular maintenance.
  • Brass products with high zinc concentration may be susceptible to dezincification.
  • Stress cracking on the surface may appear over time.

Surface Treatment and Post-Processing of Brass Parts:

As previously mentioned, corrosion resistance is one of the valuable advantages of using brass for manufacturing products and parts with CNC machining, with excellent corrosion resistance and highly attractive fittings. So most times, the surface doesn't need any coating. However, you can use manual polishing or tumbling in decorative applications.

Applications of CNC Machined Brass Parts:

CNC machined brass parts are applied across various industries due to their broad range of attributes.

  • Electrical Components:
    Some electrical components, such as fuses, connectors, standoff posts, grounding, panels, electrical meter parts, power sockets, are made through brass CNC machining because of brass's conductive properties.

  • Heating Equipment:
    High-temperature fittings include thermostats, radiator cores, evaporators, heat exchangers, piping, and tanks.

  • Automotive Parts:
    Wheels, gears, valve stems, couplings, adapters, odometer contacts, and more can be manufactured via brass CNC machining.

  • Plumbing and Hardware:
    Faucets, bathtubs, piping, valves, shower doors, bathroom partitions, and other fittings.

  • Joining and Linking:
    In manufacturing, fastening components such as nuts, bolts, wear plates, flanges, fasteners, and bushings are indispensable. These products can be made with brass CNC machining, featuring high precision and smooth surfaces.

  • Hydraulic Components:
    Pumps, power cylinders, pressure conveyance systems, pistons, and more.

  • Military:
    Various missile components, gun casings, ammunition primers, and more.

  • Aircraft:
    Aircraft landing gear, brakes, cockpit parts, undercarriages, cargo doors, and more.

  • Structural and Architectural:
    Brass CNC machining is adopted in architectural implementations, including finger plates, door furniture, rainwater systems, handrails, balustrades, panels, fittings, and roofing.

  • Medical Components:
    Although brass isn't widely used in surgical equipment, parts for needles, scissors, surgical knives, pressure regulators, and pressure control devices are made with CNC machined brass parts.

  • Other Applications:
    Other products and parts are made with brass CNC machining, such as clock parts, musical instrument parts (trumpets, horns, trombones, and baritones), jewelry, and other decorative items.

Final Thoughts:

The benefits of products manufactured with CNC machining in brass include machinability, tool compatibility, shorter cycle times, durability, recyclability, dimensional stability, and more. Additionally, it's evident how they collectively enhance productivity and profitability in such cases. Therefore, the material is relatively affordable and practical, so you can contact us immediately for any brass machining using CNC machines. Moreover, ProleanHub also offers specialized CNC machining services for brass parts. Here, our quality control engineers monitor every machining step to maintain standards and tolerances.

FAQs:

  • How can productivity in CNC machining of brass parts be improved?
    Proper tools, conditions, and equipment should be used when machining parts to improve productivity.

  • Is brass CNC machining the right choice for my project?
    Brass has excellent mechanical properties that vary with zinc content. CNC machining is also economical and easy. So it's suitable for your project. Just let us know what component or product you're looking for. Our experienced engineers will assist you. You can also check out our guide on CNC Copper Machining; it will help you decide between brass and copper.

  • How to choose the best brass alloy grade?
    It depends on the application of the product and the necessary mechanical and physical qualities, including hardness, strength, ductility, and conductivity. Since each type of alloy has unique properties, choosing the best grade can be challenging.

So let our professionals decide the most suitable for CNC machining based on your requirements.

  • What factors should be considered when selecting a brass grade?
    You should consider four key factors: corrosion resistance, strength, machinability, and appearance.

  • Do brass machined parts require surface treatment?
    Most parts do not require any coating post-processing, but manual polishing would be better for decorative items.