Factors affecting the cost of CNC Machining

Equipment and machinery

Equipment costs are incurred before the process begins. However, equipment and machinery are the costs of production preparation and ultimately affect the processing plan. The more expensive it is to acquire, operate and maintain a machine, the more expensive the parts made from that machine will be.

Production reserve cost

Production preparation costs are all costs incurred in preparation for actual processing. All CNC Machining parts start with 3D models, which are designed using CAD (computer aided design) software after machining. The resources required to design a 3D model for production account for a large part of the production preparation cost. Production readiness costs also include all costs associated with design optimization and preparation for model production using specialized CAM software (computer-aided machining).

Material

The materials needed to make a part is one of the most important cost factors. There are a lot of costs associated with materials to be processed. The first is the cost of the materials themselves. Materials are priced differently, depending on their availability, material characteristics and overall production cost. Metal materials are usually more expensive than other materials. The chart below depicts the relative prices of some common engineering metals. It should be noted that metal prices fluctuate up and down, the exact price may vary by region, the table below is a relative price reference. In addition to the cost of materials, machinability is another important cost determining factor. Materials with low machinability will take more time and energy to process, but in the field of CNC Machining, time is money. The cost of a processed part is directly proportional to the time it takes to process it. Difficult-to-process materials also consume more resources, such as cutting fluid, electricity and cutting tools.

Design and geometry

The design and appearance of parts greatly affect the cost of CNC Machining. A good rule of thumb is that the more complex a part is, the more expensive it is to make. Complex parts may require the use of more advanced machines, as well as longer processing times, multiple processes and assemblies, more resources and more careful quality checks -- all of which affect the cost of the part. Specific parts characteristics and designs in CNC Machining inevitably lead to cost increases, including sharp inner corners, thin walls, deep cavities, non-standard hole sizes, lettering, etc. These and the other high cost parts features we have summarized all have a significant impact on cost and should be avoided if not necessary. In addition, specific design requirements, such as surface roughness or tolerance options, may require multiple finishes and quality checks. And, in theory, bigger parts cost more, because more raw materials are needed and more manufacturing resources and time are invested.

Yield

As the number of parts increases, the unit cost of making an identical set of parts falls. This scaling down of costs is attributable to the elimination of redundant production preparation costs. Preparation costs such as CAD design, CAM preparation and machine installation are all done in one go for the same set of parts to be manufactured.