Factors that affect CNC machining cost

Factors that affect CNC machining cost

Irrespective of the machine shop you choose to work with, the pricing of the CNC machining processes will vary depending on various factors. These factors include:

Material selection

The choice of material to be used for the machine components influences cost in two ways: raw material cost and material machinability cost. Some materials are more expensive as a raw material than others while others are more difficult to fabricate than others. The lower the material machinability, the more expensive it is. In the event that the material to be used is potentially hazardous then additional safety precautions are required hence the cost of production goes up. The choice of material used significantly impacts on the overall price of the machine. At 3ERP material we use mostly for CNC machining are:  METALS-Aluminum, Copper, Titanium, Stainless Steel, Magnesium, Zinc; PLASTICS-ABS, Acrylic, Delrin, Fiberglass, PEEK,PVC, Polycarbonate, Polyethylene, Polyurethane, Teflon, Ultem.

Quantity of parts

The number of parts ordered for a machine influences the overall cost. This is because large orders are expensive, however the higher the number of parts the lower the cost of each additional unit. This means large orders increase the final cost of the part but reduce the cost per unit. The turnaround time for the parts is also important in determining cost as a part to be shipped in a number of weeks will be more affordable than that to be shipped in two to three days.

Part geometry

This refers to the dimensions of a part. The larger a part is, the more material it will require to be manufactured hence the more expensive it will be. Complex and very detailed parts also increase costs significantly. This is because of the multiple processes that will be needed to be employed as compared to simpler parts. Designing unnecessarily expensive parts in the design phase of a machine is very easy and thus is advised to consult a knowledgeable manufacturer at the time to enable you to come up with a functional yet efficient part to manufacture.

Manufacturing equipment required

Modern machining and manufacturing equipment vary and are extremely expensive. It is important to know whether a part can be completed using one multi-axis machine or will require multiple machines. As well as how many different machines and operations will be needed. The size and capability of the equipment needed will add to the factors that will influence of the overall cost incurred. At 3ERP we equipped with HAAS 3, 4, 5 axis cnc machines in-house.

Part tolerances

This refers to how close the physical part needs to be to the design submitted. It is usually measured in hundredths or thousandths of an inch. Unnecessarily tight tolerances on a part increase the overall cost due to its complexity and demand. Tight tolerances should be reserved for where the part interfaces with others. Our typical tolerance accuracy ranges from +/-0.02mm to 0.1mm, depending on customer’s requirement.


The machinists involved in creating a part have to be paid for their work. If a part is difficult, more complex and requires the expertise of more highly and trained machinists the cost of production goes up. These extra skills and experience come at a cost because they are mainly obtained from on-the-job experiences and not formal education. The more labor intensive the production of a part is the higher its pricing will be.

Additional treatments and finishing processes

If your part requires additional treatments, the overall cost is bound to go higher. These treatments include heat treatments, specialized coatings, anodizing, surface finishing and specialty machine operations. These treatments should, however, be evaluated for necessity and value before carrying them out. Part surface finishing including: Painting, Anodized, Chromed, Metallizing & Chrome Sputtering, Blacking, Silk-Screen, Water Transfer. To find the most suitable surface finishing for  your parts, we will write another article to explain that.


Inaccurate and incomplete CAD drawings may end up in becoming very costly in the production of parts. This is because incorrect information on the models may lead to manufacturing a part twice just to get exactly what it is you wanted because your drawings did not initially communicate that effectively. Consulting an experienced machinist or engineer during the design phase may add initial cost to the project but will save much more in the long run.

The above factors should be carefully considered when deciding to embark on a CNC machining project to have a clear indicator on an expected budget. Contact 3ERP and send through the CAD files to get a project review today, to see what our CNC experts can help your project.