Some challenges a manufacturer may face producing CNC turning/milling brass parts
Most types of brass are the cheapest alloys of non-ferrous metals based on copper. Thus, engineers used this type of metal for fittings or other parts. Brass parts are mainly used in food and medical industries as well as in thermal systems. Unfortunately, there is no perfect type of metal or alloy. Brass has a set of disadvantages you need to consider designing devices, mechanisms or even single parts.
Complex corrosion process of brass
All metals are subject to corrosion to some extent. Therefore, all manufacturers recommend carrying out anticorrosive processing from time to time. However, when it comes to brass the anticorrosive processing may have an opposite effect. The anti-corrosion inhibitor can remove zinc atoms from the alloy. This process is called dezincification.
That leads to significant changes to the properties of the part. The point is that copper has a lower degree of reactivity compared to zinc. If brass consists of less than 15% of zinc it is less susceptible to dezincification. However, if there is more than 15% of zinc in brass alloy then zinc is easier to be removed from the alloy during anticorrosive processing.
By the way, did you know that you can roughly determine the amount of zinc in a brass alloy with a naked eye? All you need to do is to compare the color of the sample with a pure copper. The more the colors differ the more zinc is in a brass alloy. Therefore, the level of dezincification can be determined easily as well. The more zinc is removed in this or that area of the part the more color becomes closer to pink. Such effect can be easily tracked on the old wind musical instruments. The process of losing zinc atoms becomes a real problem for restores. Modern engineers should bear in this mind projecting their products.
Relatively fast wearability
Brass is way cheaper than bronze. Thus, it is widely used in the production of cost-effective parts and components. However, its wearability is also way faster especially when it comes to mechanical interaction with other parts. To put it simply, it is recommended to use brass for the fixed parts (i.e. fittings) and bronze for the moving parts. However, this is not a universal recommendation.
It is considered that brass is easier to process than bronze. That is true however, with modern equipment it is no longer a point. It was a crucial factor for old machines where the processing time depended on the hardness of the alloy. Nowadays, modern CNC turning and milling machines can process parts equally fast regardless of the hardness of the material. The only difference is the tool that will be chosen to machine brass or bronze components.
Lead content in brass
Keep in mind that manufacturers add lead to some types of brass. It is made to increase machinability and provide pressure tightness by sealing the shrinkage pores. However, this factor does not have a significant influence on the price of the alloy. Please note that the sanitary and hygienic norms of the European Union and other countries around the world strictly regulate the content of lead in parts and components especially when it comes to food or medical industry. Therefore, it is recommended to check the composition of alloy and receive all the necessary certificates and documents from a manufacturer prior to starting your project.
Order CNC brass parts and components with B&K Precision Machining
We have experience in CNC machining of all types of brass alloys. We buy non-ferrous metals and their alloys exclusively from European Union suppliers. Our company guarantees to process orders of any complexity at the shortest lead time. Order CNC machining of brass components made according to your drawings with us.