Milling has been a go-to process for metalworkers since the 1800s, though the way it’s done has changed dramatically. In the past, the procedure necessitated a lot of manual work, but now it’s mostly automated thanks to Computer Numerical Control (CNC) technology. Once the tooling is set up, CNC machining technology offers complete automation, reducing the possibility of human error in most cases and increasing the speed and complexity of the parts handled. However, it’s crucial to consider the cost of CNC machining when planning a project. This article delves into the various factors that influence CNC milling expenses.


The overall cost of CNC milling is shaped by several factors, including:

  • **Machine Size**: The size of CNC machines determines the size of parts that can be manufactured. Sophisticated CNC machines required for producing larger parts cost more than those required for smaller components.
  • **Cutting Tolerances**: Tighter tolerances provide greater accuracy in the final product. However, a high-quality machine that can perform precise cuts to tighter tolerances costs more. Consequently, tighter tolerances increase the CNC machining cost of a project.
  • **Number of Axes**: The complexity of parts produced through CNC machining is dictated by the number of axes. Multi-axis machining offers greater manufacturing freedom and capabilities, but the use of 5-axis and 6-axis machines significantly increases the project’s cost.
  • **Milling Time**: Machines that manufacture parts faster require special robotics in the CNC mechanism, leading to higher start-up costs. However, modern CNC machining uses high-speed robots that can produce a high volume of products in a short time, leading to lower overall CNC machining costs due to better utilization of time.
  • **Type of CNC Machine/Mill**: The type of CNC mill used can impact the overall cost of CNC machining operations. Different types of mills, such as bed, box, C-shape, and gantry mills, have varying costs. Simple designs and geometries reduce costs.
  • **Part Geometry**: The dimensions of a part, which increase with its size, require more material to manufacture, making it more expensive. Complex and detailed parts also increase costs significantly due to the multiple processes that need to be employed as compared to simpler parts.

When designing parts in the machine’s design phase, it’s essential to consult knowledgeable manufacturers to ensure that functional yet efficient parts are created and not unnecessarily expensive ones.