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grade of torlon

Which grade of Torlon would be optimal for your CNC project?

Whether you're a hobbyist or a seasoned professional, selecting the right materials for your CNC projects is crucial.

One high-performance plastic that often comes up in these discussions is Torlon.

Known for its exceptional strength, stability, and resistance to harsh environments, Torlon can be the secret ingredient to a successful CNC project.

But it's not just about choosing Torlon; it's about choosing the right grade of Torlon.

Understanding Torlon: History, Characteristics, and Uses

Before diving into grades, let’s understand Torlon PAI better. Torlon, or polyamide-imide, was first developed in the 1960s by the American chemical company Solvay Specialty Polymers.

Torlon plastic is celebrated for its robust mechanical strength, exceptional resistance to wear, creep, and chemicals, and high thermal stability spanning a significant temperature range. This attribute underscores its ability to retain its key properties even under extreme heat, thereby enhancing its performance in high-temperature applications.

Furthermore, its superb chemical resistance enhances its resilience to degradation in demanding environments, thus bolstering its durability and longevity. Whether it’s about enduring thermal stress or resisting chemical attacks, Torlon plastic’s exceptional attributes make it a stand-out choice for applications demanding robustness and longevity.

These features render Torlon Material ideal for demanding applications in CNC projects and diverse sectors, such as the aerospace, automotive, and electrical industries. So, whether dealing with corrosive substances or requiring superior material strength, Torlon’s advanced properties make it a go-to choice for high-performance applications.

Grades of Torlon: Explanation and Comparison

While there are several grades of Torlon, four primary grades are frequently used in machining. These include Torlon 4203, Torlon 4301, Torlon 4435, and Torlon 5030.

Torlon 4203

torlon 4203

Torlon 4203, also recognized as Torlon AI-10, is the electrical grade of Torlon, renowned for its exceptional strength and stiffness up to 275°C. This grade is characterized by superior electrical insulative properties, which maintain stability across a broad spectrum of temperatures and frequencies. Even with a slightly high moisture absorption rate compared to some other Torlon grades, it consistently exhibits excellent performance, thus making Torlon 4203 an optimal selection for high-temperature electrical and electronic applications that can tolerate a degree of moisture exposure.

Torlon 4301

torlon 4301

Torlon 4301, also referred to as Torlon AI-30, stands out as the wear-resistant grade of Torlon. It’s distinctive for its remarkable compressive strength and low coefficient of friction, which makes it particularly suitable for non-lubricated, high-load, and high-speed applications. Further enhancing its application versatility is its excellent thermal stability. This attribute enables Torlon 4301 to maintain its structural integrity and performance even under high-temperature conditions, extending its usability in thermally challenging environments. Commonly, you’ll find Torlon 4301 employed in applications such as bearings, thrust washers, seal rings, and gears, where its unique combination of wear resistance and thermal stability are truly indispensable.

Torlon 4435

torlon 4435

“Torlon 4435, engineered for its exceptional compressive strength and creep resistance, is ideally suited for high-load mechanical applications. Its characteristic resilience to wear and chemical attack enables it to function efficiently in adverse environments and across a broad temperature range. Torlon 4435 maintains its mechanical and dimensional stability with a high glass transition temperature even under considerable thermal stress. This attribute further underscores its suitability for demanding applications where other materials might fall short due to heat deformation. Hence, Torlon 4435, with its robust properties and high glass transition temperature, emerges as an optimal choice for challenging, high-temperature applications.

Torlon 5030

torlon 5030

Torlon 5030, a 30% glass-reinforced grade, stands out with its exceptional rigidity and dimensional stability. It exhibits a lower coefficient of linear thermal expansion and superior creep resistance compared to other grades and excels in retaining custom geometries. This makes it especially suited for high-stress structural components where maintaining shape integrity over a broad temperature range is critical. So, whether your project demands High precision or enduring performance under thermal stress, Torlon 5030 emerges as an optimal choice.

The following table provides a general comparison:

PropertyTorlon 4203Torlon 4301Torlon 4435Torlon 5030
Tensile Strength (psi)18,00016,00018,00018,000
Flexural Modulus (psi)500,000500,000500,0001,200,000
Compressive Strength (psi)24,00026,00030,00032,000
Maximum Service Temp (°C)260275275270
Wear ResistanceGoodExcellentGoodGood
Creep ResistanceGoodVery GoodVery GoodExcellent
Moisture Absorption (%)
Electrical PropertiesExcellentGoodGoodGood
Use this table to compare Torlon grades and their traits, aiding in selecting the suitable grade for your application.

Choosing the Right Grade of Torlon for Your CNC Project: Factors to Consider

torlon machined part
Torlon Machined Part

Required Mechanical Properties

For instance, if your CNC project involves parts that will be under a constant or heavy load and need to maintain their structure over time without deforming, then you should consider Torlon 4435 or Torlon 5030. These grades have excellent compressive strength and creep resistance, making them ideal for high-load mechanical applications.

Environmental Conditions

Let’s say your CNC parts will operate in an environment with fluctuating or extreme temperatures. Torlon 4301 and Torlon 4435, with their high maximum service temperatures, could be excellent choices. On the other hand, if the parts are exposed to moisture, you might want to opt for Torlon 5030, which has a lower moisture absorption rate.

Design Complexity

Materials with high dimensional stability are preferable for intricate or highly detailed designs as they maintain their shape over a wide temperature range. Torlon 5030, a glass-reinforced grade, would be an ideal choice in this case.


While all Torlon grades offer superior properties, some grades might be more expensive than others due to their unique properties or the complexity of their production process. Choosing a grade like Torlon 4203, which provides excellent properties at a relatively lower cost, could be more suitable for a budget-conscious project.

Specific Application of Your Project

For parts like seals, bearings, and gears, which need high wear resistance, Torlon 4301 would be the go-to grade. On the other hand, if your project involves high-impact parts such as bumpers or impact-resistant cases, then Torlon 4203, known for its toughness, would be a great choice.

Case Study: Successful CNC Projects with Different Torlon Grades

torlon cnc part
Torlon CNC Parts

Case Study 1: Torlon 4203 in Aerospace Industry

A manufacturer in the aerospace industry required a material that could withstand high mechanical loads and offer excellent electrical insulation for some components within their aircraft systems. Their CNC machined parts were expected to resist impacts and shocks while maintaining high performance under extreme temperature conditions. They selected Torlon 4203 for its combination of high strength, impact resistance, and excellent electrical insulation. The CNC-machined components performed admirably in rigorous testing and real-world applications, underlining the benefits of Torlon 4203 for such high-demand applications.

Case Study 2: Torlon 4301 in Automotive Manufacturing

A high-performance car manufacturer needed a material for their transmission components that would endure high friction, temperature, and wear resistance. They chose Torlon 4301, a grade known for its excellent wear resistance and low friction properties. After being CNC machined into precision components, these parts demonstrated exceptional performance in the transmission systems, outperforming other materials and leading to lower maintenance costs and longer life for the transmissions.

Case Study 3: Torlon 4435 in Industrial Equipment

An industrial equipment manufacturer needed to create durable, long-lasting components that would be exposed to constant heavy loads. They opted for Torlon 4435, renowned for its superior compressive strength and creep resistance. The CNC-machined parts, once installed, maintained their shape and functionality over a long period, leading to reduced downtime and increased productivity.

Case Study 4: Torlon 5030 in Precision Instrumentation

A company specializing in precision instruments needed to produce structural components that would maintain their dimensions over a broad range of temperatures. They chose Torlon 5030, a 30% glass-reinforced grade known for its high rigidity and dimensional stability. After CNC machining and assembly, these components provided the necessary precision and stability, greatly enhancing the reliability and accuracy of the instruments.


In conclusion, choosing the right grade of Torlon for your CNC project is crucial, and it’s a decision that can significantly impact your project’s overall quality and success. At AT-Machining, we understand the unique properties and benefits of each Torlon grade, and we’re experts at CNC machining with this high-performance plastic.

torlon cnc machining services 1
Torlon CNC Machining Services

Whether you need the excellent electrical insulation of Torlon 4203, the wear resistance of Torlon 4301, the superior compressive strength of Torlon 4435, or the dimensional stability of Torlon 5030, we have the expertise and experience to deliver high-quality, precision-machined parts for your specific application.

At AT-Machining, your project’s success is our priority. Let us help you make the most of the exceptional properties of Torlon in your next CNC project.

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