The cost of CNC milling depends on multiple factors such as type of material used, complexity of design as well as number of parts. In order to decrease costs it is important to completely understand all of these factors.
In this blogpost we will explain the main factors that affect CNC milling prices and also offer practical steps to reduce costs.
What is CNC Milling?
Basically CNC milling is a manufacturing method in which material is removed from a solid block to create custom‐shaped parts. It uses computer‐controlled rotating cutters to obtain accurate results. This process depends on CAD models & G‐code to guarantee consistent quality and high accuracy.
Also See: A Complete Guide to CNC Milling
Main Factors That Affects CNC Milling Costs
1. Tooling & Setup
In CNC milling, tooling & starting setup charges are a large part of the initial cost. These charges include tool preparation, fixture creation as well as programming. Costs change considerably－from around $50 for basic parts to over $1,000 for complex designs that need a large number of setups.
2. Material Type
The expense of CNC milling relies largely on material chosen. Premium materials like titanium cost $30‐$50 per kg. Whereas aluminum, which is an affordable & common choice, usually costs between $1‐$3 per kg.
An additional main factor is machinability. Materials that can be easily machined decrease tool wear and processing time. On the opposite harder materials, like titanium or stainless steel, need slower machining speeds and special cutting tools, which increases costs.
3. Batch Size & Quantity
The number of parts in the production has a large impact on cost performance. Large‐scale manufacturing usually reduces the cost per unit because of the benefit of Economies of Scale. It is the result of fixed cost of the setup being divided into more parts.
In case of small orders, the costs per unit are elevated as the installation fee is still the same irrespective of quantity.
4. Design Complexity
The complexity of component design also affects the cost of CNC milling.
Complex designs with tight tolerances or numerous features increase machining time & programming. These complex components usually need advanced software, expert programmers as well as extra machine setups. Moreover features such as high‐precision details or internal cavities may require micro‐milling techniques or special machinery which increases the cost even more.
5. Number of Axes
The hourly rate of CNC milling machines changes with the number of axes they contain.
For instance 3‐axis machines usually cost between $30 to $100 per hour.
In contrast 5‐axis machines range from $75‐$200 per hour because they can decrease number of installations needed & can handle highly intricate geometries.
Also See: 3-axis vs 5-axis CNC Machining
6. Cutting Tolerances
The necessary tolerance level has a big impact on cost of CNC milling. Tight tolerances－i.e ±0.01 mm－increase costs as they require special tooling, slower machining speeds as well as modern inspection equipment.
Furthermore tight tolerances have a greater risk of defective parts which require more detailed quality inspection. Picking loose tolerances－such as ±0.1 mm－can decrease total costs but accuracy may be reduced. This is why thoughtful choosing of tolerance levels is necessary to balance costs.
7. Post‐Processing Demands
Extra post‐processing steps add costs but increase the performance & appearance of CNC machined components. Common processes like deburring cost between $5‐$10 per part. Advanced finishes like powder coating or anodizing cost between $50 and $200 which depends on the selected material & complexity.
See Also: Powder Coating vs Anodizing
8. Machining Time
The operating time of a CNC machine has a profound impact on expense of milling. Machining hard materials or complex designs takes longer which increases costs. Moreover labor costs also increase the total cost.
9. Lead Time
Requesting a shorter lead time often increases costs as faster machine scheduling & labor management are required. Simpler parts need less time to manufacture. However availability of machines, complexity of design as well as types of materials chosen also greatly affect the manufacturing timeline.
10. Labor Cost
Labor costs comprise expenses related to machine setup, CNC programming, operation as well as quality control processes.
CNC programmers typically charge $30 to $50 per hour. Likewise machine operators make hourly earnings in same range. Complex projects that require accurate tooling, expert‐level skills or detailed design incur greater labor costs. Hand‐operated inspection and other labor‐intensive activities can also increase these expenses.
Practices to Minimize CNC Milling Costs
Minimizing CNC milling costs need careful decisions related to production methods & part design. The following given solutions can help decrease costs without affecting part functionality & quality.
Reliable Manufacturer
Picking a reliable CNC machining supplier is very important to attain high‐quality & cost‐effective results. Professional manufacturers－such as Richconn－can recommend improved design changes, better production methods as well as lower‐cost materials.
Furthermore partnering with a reliable supplier reduces costly rework, decreases errors and guarantees on‐time delivery.
Simple Part Design
Decreasing complexity in your intended part design reduces machining time which lowers total costs. Exclude features such as complex geometries, deep cavities or undercuts that demand special tooling or extra setups.
Regulating Length of Threads
Overly deep threads increase machining time and increase the risk of tool damage as well. In general a thread depth greater than 3‐times the hole diameter does not greatly increase the strength of the joint. For blind holes, leave extra unthreaded space below to reduce expense and facilitate the machining process.
Production Volume
Large‐volume production is a practical way to decrease CNC milling costs. Bulk production spread the setup cost over more units which reduces cost per unit by economies of scale.
Limiting Multiple Finishes
Choosing multiple surface treatments－i.e anodizing in one part & bead blasting in another－increases the number of processing steps. This increases overall costs. To maintain less expense consider leaving surfaces untreated where possible or using a uniform finish.
Thin Walls
Parts with very thin walls easily get damaged which requires reduction in machining speed. To avoid this, you have to maintain a wall thickness of at least 1.5 mm for plastic parts & at least 0.8 mm for metal components. Thicker walls guarantee less vibrations, higher stability and lesser machining times.
Avoiding Sharp Edges
Sharp‐edged internal corners complicate machining which demands extra processing & special tools. To facilitate machining use fillets and ensure that their radius is at least 30% greater than the radius of the cutting tool. This method decreases tool wear, machining time as well as total cost.
Large Batches
Manufacturing components in large‐batches distribute the setup costs over more units which decreases cost per item. Bulk production also decreases material waste and increases machine usage which further increases cost efficiency.
Cost‐Effective Materials
The choice of material largely impacts cost of CNC milling. Aluminum alloys－particularly 6061‐T6－are easy to machine & inexpensive whereas mild steel provides strength at a lesser cost. For prototyping purposes, plastics－i.e POM & ABS－are low‐cost alternatives that still provide acceptable quality.
To Sum Up
Understanding factors that affect cost is necessary for better budgeting for CNC milling. Companies or industries can significantly reduce milling costs by picking right materials, improving design as well as increasing production volumes．
If you need any kind of CNC machining services customized to your needs, then Richconn is your best option. You can contact us anytime.
Related Question
Is CNC milling more budget‐friendly than 3D printing?
CNC milling is more budget‐friendly for simple components & big quantities. Whereas 3D printing gives lesser costs for manufacturing detailed designs or small quantities.
What is the usual cost of CNC milled parts?
CNC milling rates range from $20‐$350 per hour. The complexity of design, type of material and the particular CNC machine used－such as 3‐axis or 5‐axis－affect the final cost.
Why do CNC shops charge setup fees on small orders?
CNC shops charge setup fees because it takes a lot of effort to program, prepare tools as well as adjust machines. These operations require the same amount of effort irrespective of order size.
Will giving your own materials decrease the cost of CNC milling?
Yes, by giving your own material you can reduce purchasing costs and lower total costs as well. But there are risks to this practice. Material reliability problems or incompatibility with CNC operations can occur which can possibly raise machining costs.
Do extra surface finishes like bead blasting or anodizing greatly increase cost?
Surface finishes such as bead blasting or anodizing usually increase the total cost. This is because of special tools & extra processing steps required to attain durable and uniform results.
Is CNC milling a cost‐effective option for prototyping single components?
CNC milling can be cost‐effective for producing functional & accurate prototypes. But for the manufacturing of single components the starting setup costs can make the process comparatively expensive.
How does picking recycled materials over pure ones determine CNC milling expense?
Using recycled materials can decrease expense a little bit but it carries risk of irregularities in the final result. On the other hand pure materials are more dependable specially for parts that need tight tolerances.
How do CNC milling & CNC turning compare in terms of cost?
CNC milling is generally more expensive because it needs tooling & complex setup. On the other hand CNC turning is generally more cost‐effective specially for symmetrical components.
How do CNC machine tolerances (±0.01 mm vs. ±0.1 mm) affect cost?
Picking tighter tolerances increases cost of CNC machining. This is because tighter tolerances need special tooling, slower machining processes as well as greater scrap rates.
Does selection of software file format (STEP vs. STL) affect the expense of CNC milling?
File formats can affect the cost of CNC machining. STEP software file format is normally considered better due to the fact that they have thorough geometric knowledge. This decreases errors & programming effort. On the other hand STL files need extra conversion.
