CNC Machining for Precision Components: Key Considerations for Better Results

Precision Components

CNC Machining for Precision Components: Key Considerations for Better Results

When customers need precision machined components for applications like industrial automation or robotics, CNC machining is likely their manufacturing method of choice. 

This process is capable of producing high volumes of metal components with an extreme degree of precision and accuracy. But before selecting an outsourced manufacturing partner for CNC machining services, it’s important to know that they can deliver exactly what you need. 

If you’re interested in incorporating CNC machining into your manufacturing process, here are four considerations for optimizing quality, cost, and lead time with your outsourced manufacturing partner. 

4 Considerations for CNC Machined Precision Components  

Critical attributes.

Getting a high-quality component is of paramount importance, but when it comes to CNC machining, more isn’t always better. Overengineering a part increases cost and lead time, so it’s important to find an outsourced manufacturing partner that can help you identify and define the 1-2 critical attributes that are essential to the function of your component. 

For example, if a sealing area requires a certain finish to work properly, then focusing on the surface finish should be the priority. If standard tolerances are sufficient for your part to function, there’s no need to over-tolerance the component—it can drive up cost and lead time. 


Precision Components

Machining tolerances refer to the range of permitted variance in the dimensions of a part or component. Standard tolerances typically measure ± 0.005”, while tight tolerances can be as miniscule as±0.001”—a fraction of the width of a human hair.  

Precision components often require extremely tight tolerances to meet required specifications. If the tolerances are too loose, components may not fit into place or function properly. Considerations like design complexity, material, tooling, and equipment all factor into a machine shop’s ability to achieve tight tolerances. Only the best CNC machining partners have what it takes to consistently guarantee tight tolerances for precision components. 


Surface finish accounts for the roughness or smoothness of a component, and is measured in RMS, or root mean square. A standard machined finish falls in the range of 80-120 RMS, with mirror surfaces requiring an even higher RMS. The more exacting the finishing requirements are for a precision machined component, the more time, tooling, and expertise go into manufacturing it. 

For certain components, like ones with sealing areas, achieving an exacting surface finish is critical because if the surface is too rough or too smooth, the seal may not function properly. Surface finishes are also important for customer-facing parts that must meet high aesthetic standards. 

If, however, the surface finish doesn’t factor into the function or outward appearance of a part, it’s possible to save time and money by minimizing exacting finish requirements. 

Quality assurance processes. 

Standardized quality assurance processes are essential for ensuring that precision machined components meet all critical requirements. There are a range of techniques for inspecting and measuring components, so customers and their CNC machining must get on the same page about which methods they are using. 

Why? Because using different measurement tools, like a ruler vs. a digital caliper, could lead to varying results. Agreeing on the technique, technology, and approach helps to ensure consistent quality assurance across both parties. 

CNC Machining Services at Alchemy Industrial 

Alchemy Industrial is proud to provide CNC machining services (milling, turning, 5-axis machining, and Swiss screw machining) in addition to our 3D printing services. 

We specialize in machining precision components like seals, bearings, gears, pins, housings, and valves for applications like industrial automation and robotics. Common materials we work with include,

  • Plastics such as ABS, acrylic (plexiglass), delrin (acetal), HDPE, nylon, polycarbonate (Lexan), polypropylene, PTFE, UHMWPE and PEEK.
  • Metals include a variety of grades of aluminum, brass, steel and stainless steel. 

If you’re looking for an outsourced manufacturing partner for CNC machining services, reach out to us today to discuss your precision components.