There are the potential challenges in CNC machining brass and copper：

l Work Hardening: Both brass and copper are susceptible to work hardening, which can increase the material's hardness and reduce its machinability. Employ appropriate machining strategies, such as using sharp tools and optimizing cutting parameters, to minimize work hardening.

l Chip Formation: Brass and copper can produce long, stringy chips that can wrap around the tool, causing tool breakage and poor surface finish. Use chip breakers on cutting tools and implement effective chip removal methods to prevent this issue.

l Tool Wear: The relatively soft nature of brass and copper can lead to rapid tool wear, especially when machining at high speeds and feeds. Use high-quality cutting tools with appropriate coatings and monitor tool wear closely to ensure consistent part quality.

l Thermal Conductivity: The high thermal conductivity of copper can cause rapid heat generation during machining, which can lead to tool wear and dimensional inaccuracies. Employ effective cooling methods to manage heat and maintain dimensional stability.