{"id":3167,"date":"2025-05-14T11:33:48","date_gmt":"2025-05-14T03:33:48","guid":{"rendered":"https:\/\/chiggofactory.com\/?p=3167"},"modified":"2025-05-14T11:46:06","modified_gmt":"2025-05-14T03:46:06","slug":"brass-cnc-machining","status":"publish","type":"post","link":"https:\/\/chiggofactory.com\/hi\/brass-cnc-machining\/","title":{"rendered":"A Comprehensive Guide to Brass CNC Machining"},"content":{"rendered":"\n

Brass is a non-ferrous metal<\/a> commonly used in various industries for different purposes. From complex electronic connectors and durable plumbing fittings to high-performance automotive and aerospace components, brass is almost everywhere. Its ability to be machined with high accuracy makes it a top choice in manufacturing.<\/p>\n\n\n\n

But how are these intricate brass parts produced with such precision and consistency? The answer lies in CNC machining, an automated process that shapes brass with remarkable accuracy and efficiency.<\/p>\n\n\n\n

In this CNC machining brass guide, we\u2019ll examine brass properties, various brass grades for custom parts, available finishes, and explore how to optimize the process for superior results.<\/p>\n\n\n\n

What Is Brass CNC Machining?<\/h2>\n\n\n\n
\"Brass-CNC-Machining<\/figure>\n\n\n\n

Brass CNC machining is a subtractive manufacturing process that uses Computer Numerical Control (CNC) machines to precisely cut, shape, and drill brass workpieces by removing material. The material removal rate (MRR) depends on factors such as spindle speed, feed rate, and cutting tool choice. With proper parameter selection and rigid fixturing, CNC machining can achieve tolerances as tight as \u00b10.001\".<\/p>\n\n\n\n

Brass is an alloy of copper and zinc, and is one of the best CNC materials <\/a>due to its high machinability <\/a>and ductility. It also has good electrical and thermal conductivity, good corrosion resistance, antibacterial properties, and aesthetic appeal. Moreover, its mechanical properties can be adjusted by changing the proportions of copper, zinc, and trace elements such as tin, lead, or aluminum, enabling a wide range of hardness and toughness.<\/p>\n\n\n\n

What Properties of Brass Make It Suitable for CNC Machining?<\/h2>\n\n\n\n
\"Brass<\/figure>\n\n\n\n

Next, let\u2019s take an in-depth look at the key properties that make brass highly suitable for CNC machining:<\/p>\n\n\n\n

Highly Machinable<\/h3>\n\n\n\n

Brass is one of the easiest metals to machine. Its relatively low hardness and excellent ductility reduce cutting forces and enable smooth chip formation, while the \u03b1+\u03b2 dual\u001ephase microstructure naturally promotes chip breaking and evacuation. The alloy\u2019s high thermal conductivity rapidly dissipates heat from the cutting zone, extending tool life.<\/p>\n\n\n\n

In free\u001ecutting grades like C360, lead or sulfur additives further lower the friction coefficient, minimizing tool adhesion and wear. Together, these characteristics allow brass to be machined at cutting speeds and feed rates far higher than those used for steel and stainless steel, achieving higher material removal rates (MRR) while maintaining surface finish (Ra)<\/a> and dimensional accuracy.<\/p>\n\n\n\n

Corrosion Resistance<\/h3>\n\n\n\n

Brass is a non-ferrous copper-zinc alloy and therefore does not generate \"rust\" like iron-based metals. Its corrosion resistance primarily relies on a dense, naturally formed oxide or carbonate layer on the surface, which effectively blocks moisture and oxygen, protecting the underlying metal from further corrosion.<\/p>\n\n\n\n

The alloy composition has a big impact on corrosion performance: Aluminum brass (such as C687) forms a stable aluminum oxide film on its surface, providing excellent resistance in seawater and various chemical environments. Conversely, brass with excessively high zinc content is more susceptible to dezincification in environments containing chlorides or sulfur compounds, leading to localized porosity and a reduction in mechanical strength.<\/p>\n\n\n\n

Malleability<\/h3>\n\n\n\n

Malleability is a metal's ability to deform under compression or forming without cracking. Brass, with its high copper content, inherits the face\u2010centered cubic crystal structure of copper, resulting in excellent ductility. Low-zinc brass alloys (with zinc \u2264 35%) can achieve smooth, crack-free forming during deep drawing, bending, and stretching processes. However, as the zinc content increases, the alloy\u2019s strength improves at the expense of some ductility. Additionally, cold working causes work hardening; to restore and further enhance ductility, annealing is typically carried out in the range of 400\u2013650\u202f\u00b0C to refine the grain structure and relieve stress, ensuring subsequent forming processes proceed smoothly.<\/p>\n\n\n\n

Strength and Hardness<\/h3>\n\n\n\n

Although brass\u2019s strength <\/a>and hardness<\/a> are often overlooked, they can be precisely controlled through alloying: increasing zinc content makes brass harder and stronger, while adding aluminum, tin, or nickel can further enhance its wear resistance and load\u001ebearing capacity. As a result, brass is well suited to both finely machined decorative parts and demanding structural components.<\/p>\n\n\n\n

In CNC machining, standard brass grades can be machined efficiently and accurately with high\u001espeed steel (HSS) tools, whereas high\u001estrength or alloyed grades (such as C280, C464, and C687) benefit from carbide tooling to extend tool life and increase cutting speeds.<\/p>\n\n\n\n

Aesthetic Appeal<\/h3>\n\n\n\n

Brass, with its wide range of color variations\u2014including reddish\u001egold, bright gold, and silvery white\u2014is widely used in decorative items such as lighting fixtures, door handles, drawer pulls, and picture frames. The exact hue of brass depends on its copper\u001eto\u001ezinc ratio: higher copper content produces a warmer, reddish\u001egold tone, while higher zinc levels yield a lighter, yellowish or silvery appearance.<\/p>\n\n\n\n

Electrical and Thermal Conductivity<\/h3>\n\n\n\n
\"electrical<\/figure>\n\n\n\n

Brass typically has an electrical conductivity between 15\u201328% IACS (International Annealed Copper Standard), which is much lower than pure copper (100% IACS) but significantly higher than that of stainless or carbon steel. Its thermal conductivity generally ranges from about 100 to 125 W\/m\u00b7K, roughly 25\u201330% that of pure copper (approximately 400 W\/m\u00b7K). As the zinc content increases, both the electrical and thermal conductivities gradually decrease. When you need a material that balances decent conductivity with strength, corrosion resistance, and machinability, brass is the ideal compromise. This is why it\u2019s widely used for electrical connectors, grounding components, heat exchangers, and HVAC valve bodies. In fact, nearly all Wire EDM electrode wires are made from brass.<\/p>\n\n\n\n

Types of Brass Grades for CNC Machining<\/h2>\n\n\n\n
\"Types<\/figure>\n\n\n\n

Below are some of the most common brass grades you\u2019ll encounter in CNC shops, along with their key properties and typical uses:<\/p>\n\n\n\n

C360 (Free-Cutting Brass)<\/h3>\n\n\n\n

C360 is the go\u001eto brass for general\u001epurpose CNC work, containing approximately 60\u201363\u202f% copper (Cu), 34\u201337\u202f% zinc (Zn), and 2.5-3.7% lead (Pb). The addition of lead improves chip breaking, reduces tool wear, and enables high\u001espeed machining.<\/p>\n\n\n\n

Advantages:<\/strong><\/p>\n\n\n\n