CNC Machining Brass

CNC brass machining and its industrial characteristics

Brass is a copper-zinc alloy with outstanding machinability and corrosion resistance. Thanks to the addition of lead, as in the alloy CuZn39Pb3 (CW614N), this material reaches the reference machinability rating of 100 %. Machining brass makes it possible to achieve exceptionally smooth surfaces and precise geometric shapes. It is used above all in the electrical engineering industry and in measuring instruments.

In processes such as CNC milling and CNC turning of brass we use cutting tools with optimised geometry. Short, breakable chips minimise tool wear and reduce thermal load on the workpiece. This lets us guarantee geometric tolerances of ±0.01 mm. Process stability is key to series production of connectors and fittings.

Our production facility in Ladce provides comprehensive metal machining with direct access to the motorway network, enabling fast distribution of finished components across Europe. We also give customers technical support in optimising part design.

Custom parts from free-cutting and special brasses

Manufacturing parts to drawing requires thorough analysis of the incoming material. Alongside standard free-cutting brass we also process lead-free variants (such as CuZn21Si3P) that meet strict RoHS environmental standards. These modern alloys require specific cutting conditions, above all adjusted feed rates and cutting speeds. The result is an environmentally safe product suitable for the food industry.

Custom part production covers both rotating and prismatic components. On multi-axis machining centres we carry out complex operations in a single setup, eliminating errors where surfaces meet. This approach significantly shortens production times and increases overall efficiency. Every production batch undergoes strict in-process inspection.

To achieve maximum surface quality we apply dedicated finishing operations. The most frequently machined alloys include:

• CuZn39Pb3 (CW614N): Standard free-cutting brass with excellent machinability for fast CNC brass machining.
• CuZn37 (CW508L): An alloy suited to parts requiring both machining and cold forming.
• CuZn40Pb2 (CW617N): A material ideal for more complex shapes and sanitary engineering components.
• CuZn21Si3P (CW724R): A lead-free alternative meeting the latest legislative requirements for contact with drinking water.

Process parameters for milling and turning

When milling brass blocks we use uncoated carbide cutters or cutters with a TiB2 coating, which prevents material build-up on the cutting edge. Cutting speeds for free-cutting brasses range from 200 to 600 m/min. Cooling is provided by high-pressure emulsion, which efficiently removes heat from the cut and flushes away fine chips.

Brass bar turning is carried out on sliding-headstock automatic lathes, ideal for slender and complex parts. The guide bush eliminates material deflection, making it possible to hold tight concentricity and cylindricity tolerances. This process is indispensable in producing precision shafts and contact elements for connector technology.

Toolpath optimisation in modern CAM systems reduces machine times and extends insert life. Our engineers continuously analyse cutting forces and vibration during the process. This systematic approach prevents unwanted marks on the machined surface, which is critical above all on cosmetic parts.

Quality control and applications of machined components

The final phase of the production process includes thorough inspection of dimensions and surface roughness. On brass parts we routinely achieve Ra 0.4 to 0.8 µm directly after turning or milling. Measurement takes place in a climate-controlled laboratory where conformity with ISO 2768-mK is verified. Measurement records form an integral part of the delivery documentation.

Machined brass components are used across a broad spectrum of industrial sectors. In the automotive industry these include various sensors and valves, where high electrical conductivity and corrosion resistance are required. In aerospace, brass is used for specific instrumentation that must not exhibit magnetic properties.