CNC machining is widely used for its speed and precision, but the costs can vary greatly depending on the material. You need to understand how material choice impacts CNC machining costs for proper budgeting. This article will break down how different materials influence the costs.

The machining expenses will vary depending on the CNC machining materials. Plastics are generally cheaper than metals, but some special plastic materials can be expensive. Also, high-performance alloys and harder materials often require specialized equipment, longer machining times, and higher costs. Choosing more affordable, easier-to-machine materials can reduce expenses and simplify production processes.

Read on to get a detailed comparison of some common and special variations of metal and plastic CNC machining costs. We will also share expert tips on choosing the right material for your project budget. 

Material Pricing in CNC Machining 

The material you choose is a significant factor in determining the overall CNC machining costs. Different materials come with varying prices, machinability, and post-processing needs, all of which contribute to the final cost. 

The main material cost factors are:

• Material Type: Different types of materials have different price tags. The metal CNC machining costs are often higher than plastics. For example: 
  • Aluminum alloy: $5–$15 per kg
  • ABS: $2–$4 per kg
  • Titanium alloy: $30–$50 per kg
• Machinability: Harder materials like titanium and stainless steel require more advanced tools and longer machining times. This increases tooling wear and reduces machine life, raising costs.
• Tooling and Equipment: Materials that cause higher tool wear or require specialized equipment (like titanium alloys) can lead to expensive tooling replacements and maintenance.
• Post-processing: Additional processes such as polishing, anodizing, or heat treatment can further increase costs, depending on the complexity and the material being worked with.

The impact of these factors goes into the production cost of a company. For example, if an aerospace company is machining titanium parts, the material cost could account for up to 40% of the total production cost. This example shows how selecting a high-cost material can dramatically affect your budget.

Metals vs. Plastics: Cost Comparison

Let’s find out how metals and plastics stack up in terms of cost, machinability, and applications. 

Aluminum, Steel, and Polymers  

Metals like aluminum, steel, and carbon steel are commonly used in CNC machining due to their strength, durability, and versatility. However, the cost of machining metals can vary significantly based on their properties and the complexity of the project.

a. Aluminum

Aluminum is one of the most cost-effective and easy-to-machine metals. It allows for faster cutting speeds and lower tool wear. You’ll see its use in industries like aerospace, automotive, and electronics, where its high strength-to-weight ratio comes handy.

• Average Cost (USD/kg): $5–$15
• Applications: Aerospace, automotive, electronics
• Machinability: Easy to machine with lower cycle times and tool wear.

b. Stainless Steel

While stainless steel is more expensive than aluminum, it offers better corrosion resistance, durability, and versatility. It’s commonly used in industries that require strength and reliability, like medical devices and marine equipment. However, its machinability can be more challenging, requiring careful handling to avoid issues like gummy chips.

• Average Cost (USD/kg): $15–$25
• Applications: Medical devices, kitchenware, industrial machinery
• Machinability: Can be difficult to machine, requiring proper tooling and techniques.

c. Carbon Steel

Carbon steel, particularly low-carbon grades like 1018, is one of the most cost-effective metals for CNC machining. It’s commonly used in heavy machinery and automotive parts, since it can provide high tensile strength at a relatively low cost.

• Average Cost (USD/kg): $2–$5
• Applications: Automotive, heavy machinery, tools
• Machinability: Easy to machine for standard CNC operations but may require specialized methods for high-hardness grades. 

Plastics like Nylon, Delrin, and ABS offer an entirely different set of advantages in precision CNC machining. They are lighter and easier to machine than metals, which can reduce machining times and costs. Here, we’ve discussed the costs and uses of some polymers in production CNC machining: 

d. Nylon

Nylon is a strong material that offers low friction and resistance to wear and abrasion. The budget-friendly material is often easier to machine than metals, leading to faster production times.

• Average Cost (USD/kg): $3–$6
• Applications: Gears, bearings, machine components
• Machinability: Easy to machine with good dimensional stability.

e. Delrin (POM)

The high-performance plastic is a type of acetal resin, which is tough and stiff. It’s commonly used for precision components like gears, bearings, and bushings, where tight tolerances are required. Because of having low friction properties, the material is also a good choice for mechanical applications.

• Average Cost (USD/kg): $4–$8
• Applications: Precision components, medical devices, mechanical gears
• Machinability: Machines well to tight tolerances and complex geometries.

f. Acrylic

It’s an easy-to-machine plastic that offers high optical clarity and produces clean, smooth finishes. Using this material can reduce your production costs because it’s inexpensive and requires minimal post-processing.

• Average Cost (USD/kg): $3–$6
• Applications: Displays, signage, optical components
• Machinability: Easy to machine with minimal post-processing.

g. ABS

ABS plastic is a popular material for prototyping and manufacturing functional parts in industries like electronics and automotive. CNC machining ABS offers an affordable method for creating parts with complex geometries and tight tolerances without the need for expensive molds.

• Average Cost (USD/kg): $2–$4
• Applications: Prototyping, electronics, automotive
• Machinability: Simple to machine with good results for low-cost, complex parts. 

You can contact Zintilon for high-quality CNC parts at budget prices. 

Other Metals and Plastics 

There are some less common metal and plastic options used in CNC machining and manufacturing: 

a. Brass

The metal is suitable for intricate designs and precise parts. You can use it in applications where electrical conductivity or aesthetic appeal is important. A great advantage is you can brass workpieces quickly with high-speed cutting. 

• Average Cost (USD/kg): $10–$20
• Applications: Electrical connectors, decorative items, fittings, musical instruments
• Machinability: Excellent; easy to cut and shape with high precision.

b. Copper

The metal is known for its exceptional thermal and electrical conductivity. However, it’s a bit trickier to machine due to its softness, which requires careful attention to cutting speeds and heat management. 

• Average Cost (USD/kg): $9–$15
• Applications: Electrical components, heat sinks, plumbing fittings
• Machinability: Requires moderate feed rates and good heat control to prevent tool wear.

Other than polymers, the type of plastics used in making CNC machined parts are: 

c. PEEK (Polyetheretherketone)

This high-performance plastic has properties similar to metals, including excellent strength, chemical resistance, and high-temperature tolerance. While PEEK isn’t a metal, it’s often compared to high-end alloys because it can replace metals in demanding applications, especially in aerospace and medical fields. The downside is its high cost, making it one of the most expensive materials for CNC services.

• Average Cost (USD/kg): $20–$88
• Applications: Aerospace, medical, automotive
• Machinability: Excellent for high-performance parts that need to withstand extreme conditions.

d. Polycarbonate (PC)

Polycarbonate is known for its high impact resistance and dimensional stability. It’s a great option for applications that require both toughness and optical clarity. 

• Average Cost (USD/kg): $3.1
• Applications: Optical components, protective equipment, structural parts
• Machinability: Easy to machine, with high strength and impact resistance.

e. Polytetrafluoroethylene (PTFE)

Commonly known as Teflon, PTFE is prized for its low friction and excellent chemical resistance. It’s widely used in industries where parts must withstand high temperatures, chemicals, or require non-stick properties. It requires specialized techniques to machine due to its softness and tendency to deform under pressure.

• Average Cost (USD/kg): $12–$15
• Applications: Seals, gaskets, low-friction parts
• Machinability: Machines well for specific, high-performance applications but requires careful handling. 

Metals vs Plastics for CNC Machining Cost: Comparison Chart

This table will help you understand the variation in CNC machining costs of metal and plastic materials. From the data, you can make informed decisions based on your budget and project needs.

Specialty Materials and Their Costs 

In CNC machining, specialty materials are often referred to as those that offer unique properties, performance, or characteristics not typically found in common metals like steel or aluminum. 

These materials are often used in high-performance industries where strength and resistance to extreme conditions are paramount. However, they come with their own set of challenges, particularly when it comes to cost, machinability, and the tools required to process them. 

Titanium and Exotic Metals

a. Titanium

Known for its high strength-to-weight ratio, titanium is highly resistant to corrosion and can tolerate extremely high temperatures, making it a top choice for demanding applications. The metal tends to work-harden when machined, so machining needs specialized tooling and slower machining speeds. 

• Average Cost (USD/kg): $30–$50 
• Applications: Aerospace components, medical implants, high-performance automotive parts 
• Machinability: Moderate machinability (requires slow speeds and high-quality tools due to work hardening and low thermal conductivity).

b. Inconel

Inconel is a nickel-based superalloy known for its exceptional strength and resistance to heat and corrosion. The material is incredibly tough, which can cause rapid tool wear, requiring specialized tooling and high cutting speeds. Due to its heat resistance, it’s also challenging to achieve the precision cuts required for high-performance parts.

• Average Cost (USD/kg): $60–$80
• Applications: Aerospace parts, turbine blades, chemical processing
• Machinability: High hardness and heat resistance makes machinability quite difficult. 

Other Special Materials

a. Magnesium

While it may not be as commonly used as other metals, magnesium offers excellent machinability, which sets it apart from other exotic metals. Machining it is relatively easier because of its softness compared to titanium or Inconel. The metal’s low density also reduces wear and tear on cutting tools, helping to extend their lifespan. 

• Average Cost (USD/kg): $10–$20 
• Applications: Lightweight vehicle parts, aerospace components, electronics
• Machinability: The metal is easier to cut but requires care due to flammability. 

b. Tool Steel

Tool steel is known for its high hardness, abrasion resistance, and ability to maintain its shape at high temperatures. Machining the material requires solid carbide end mills and high-speed machining techniques to prevent excessive tool wear. While more affordable than some exotic metals, tool steel can still be costly, especially in specialized forms or for high-performance grades.

• Average Cost (USD/kg): $10–$20 
• Applications: Cutting tools, molds, dies, industrial machinery
• Machinability: Moderate to difficult machinability, as it requires solid carbide tools and high-speed techniques to prevent tool wear. 

c. G10 (Glass Epoxy Composite)

This material combines high strength with lightweight properties. One of the biggest challenges of machining G10 is its abrasive nature. The material’s high hardness can quickly wear down cutting tools, especially when using conventional steel tools. You have to use diamond-coated or carbide tools and employ special techniques like wet cutting or high spindle speeds. 

• Average Cost (USD/kg): $30–$50 
• Applications: Electrical insulation, structural components, mechanical parts
• Machinability: Machining is difficult, as the metal requires special tools and cutting techniques. 

Choosing the Right Material for Your Budget 

Selecting the right material for CNC machining is crucial for ensuring both high performance and cost-efficiency. While it can be tempting to choose the most durable or premium material, it’s important to balance your project’s needs with your budget. 

Here’s how to approach material selection for CNC machining, keeping cost-effectiveness in mind.

1. Understand Your Application Requirements

Before you dive into material options, start by defining the specific needs of your project. What will the part be used for? What are its mechanical and environmental requirements? 

Consider the following factors:

• Mechanical Properties: Does your part need to be strong, hard, or flexible? Materials like steel offer high strength, while plastics like nylon are more flexible and easier to work with.
• Thermal and Electrical Conductivity: Is the material going to be exposed to high temperatures, or does it need to conduct electricity? Materials like copper excel at thermal and electrical conductivity, while others like aluminum are less efficient.
• Corrosion and Chemical Resistance: Will the part be exposed to chemicals or corrosive environments? Stainless steel and titanium are excellent choices for their corrosion resistance.
• Weight Considerations: Will weight be a critical factor? Aerospace applications often call for lightweight materials like aluminum or magnesium.

2. Analyze Cost vs. Performance Trade-offs

Premium materials, like titanium, are more expensive upfront but may offer better performance in certain applications. Less expensive materials like aluminum or plastics may work for less demanding uses.

Some materials are easier to machine, reducing production time and tool wear. For example, aluminum is easy to machine and leads to faster production times. Harder materials like stainless steel or tool steel can take longer to process, resulting in higher machining costs due to wear on tools and longer cycle times.

And you should consider a material’s durability vs. cost. While materials like titanium or tool steel may have a high initial cost, their durability could save money over time by reducing the need for frequent replacements and minimizing maintenance. Investing in a material that lasts longer can be more cost-effective in the long run.

3. Consider the Recyclability

Another factor to keep in mind when selecting a material is its recyclability. Some metals, titanium, for example, are more easily recycled than others, such as steel or copper. The higher the recycling rate, the lower the long-term cost, especially if you have the ability to reuse your material scrap. 

Here’s a quick breakdown of recyclability:

• Titanium: Almost 60% of titanium is recycled, making it a good choice for cost-saving over time.
• Steel: CNC machine shops can recycle around 47% of steel, so it’s less efficient than titanium but still a viable option.
• Copper: Only about 33% of copper is recycled, so its cost-saving potential is lower.

Choosing a material with a higher recycling rate can offset some of the initial costs and may even provide access to cheaper recycled material sources.

4. Consider Environmental and Regulatory Factors

Certain industries, like aerospace, medical, and food processing, require compliance with strict regulations regarding materials. When choosing your material, ensure it meets all the required industry standards. For example, materials used in medical devices must be non-toxic and biocompatible. Always check that your material is compliant with these regulations to avoid costly delays and penalties.

5. Assess Scalability and Availability

If you are planning large-scale production, it’s important to choose a material that is consistently available and easy to source. Materials that are in high demand or that have complex supply chains can lead to price fluctuations or delays in production. 

Make sure your material is readily available to maintain production efficiency, especially if you’re working on a tight timeline or large batch orders.

Conclusion 

Choosing the right material is an important factor to determine CNC machining costs. Whether you opt for metals like aluminum or stainless steel, or plastics like ABS and PEEK, understanding each material’s properties and machining demands will help optimize your budget. Our guide will help you make smarter material choices. 

At Zintilon, we specialize in producing custom precision parts with CNC machining services. Our expertise across industries like automotive and robotics ensures high-quality, cost-effective solutions for your needs. Get in touch to learn more about our services. 

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