CNC machining processes (including milling and turning) often leave noticeable cutting marks, which can affect the surface quality of the machined parts. Although CNC machining can provide precision parts, these machined parts require surface treatment for various reasons.
Why surface finishing CNC machining of metal parts is crucial:

Improve appearance
Surface treatments such as grinding, polishing, electroplating, or painting can help mask sharp edges and machining marks left during CNC machining. Therefore, these surface treatments make CNC machined parts more visually appealing.
Enhance corrosion resistance
Most CNC machining materials are susceptible to corrosive substances. Therefore, product designers often use surface treatments such as anodizing, polishing, and passivation to protect the surface of processed parts and ensure extended service life.
Improve the level of cleanliness and hygiene
Product manufacturers apply different surface treatments on CNC machined parts to ensure they are easy to clean and maintain. Furthermore, this is crucial in hygiene critical applications such as food processing equipment and medical devices.
Functional performance
Manufacturers use different CNC machining surface treatments to improve material properties (such as conductivity), reduce friction, and increase other required characteristics, thereby optimizing their functional performance.
customized
You can customize the surface finish of the machined parts according to your specific preferences and requirements. You can achieve different levels of smoothness to achieve a range of surface characteristics, textures, or colors.