Delrin vs Nylon: Which Material Is Better?

2026-06-10 11:41:30

When choosing materials for CNC plastic machined parts, Delrin and Nylon are two of the most commonly used engineering plastics. Both materials offer good mechanical performance, wear resistance, and processing flexibility, making them suitable for industrial components, mechanical parts, fixtures, bushings, gears, and custom precision parts.

However, Delrin and Nylon are not the same. Their differences in dimensional stability, moisture absorption, friction performance, strength, and application environment can directly affect the final performance of a product. For buyers, engineers, and product designers, choosing the right material at the beginning can reduce production risks, improve service life, and avoid unnecessary cost increases.

Shenzhen KONSTUN Precision Technology Co., Ltd. provides custom CNC plastic machining services for different industries. Based on real manufacturing experience, this article explains the key differences between Delrin and Nylon and helps you decide which material is better for your project.

What Is Delrin?

Delrin is a brand name for acetal homopolymer, also known as POM. It is a high-performance engineering plastic widely used for precision parts that require excellent dimensional stability, low friction, and good mechanical strength.

One of the biggest advantages of Delrin is its ability to maintain tight tolerances after machining. This makes it especially suitable for CNC machined parts where accuracy, smooth movement, and consistent performance are important.

Delrin also has good stiffness, low moisture absorption, and excellent wear resistance. Because of these properties, it is often used in gears, rollers, bushings, sliding parts, valve components, electronic parts, mechanical fixtures, and precision industrial components.

What Is Nylon?

Nylon is a group of synthetic engineering plastics known for toughness, impact resistance, and wear resistance. Common types include Nylon 6 and Nylon 66. Compared with many other plastics, Nylon offers high strength and good fatigue resistance, making it suitable for parts that need to withstand repeated mechanical stress.

Nylon performs well in applications such as bearings, wheels, pulleys, spacers, wear pads, industrial guides, and structural plastic components. It is also a popular choice when the part needs a balance of strength, durability, and cost efficiency.

However, Nylon absorbs more moisture than Delrin. This means its size and mechanical properties may change in humid or wet environments. For some applications, this is acceptable. But for high-precision parts, moisture absorption must be carefully considered.

Key Difference 1: Dimensional Stability

Dimensional stability is one of the most important factors in CNC plastic machining. If a part changes size after machining, it may affect assembly, movement, sealing, or product reliability.

Delrin generally offers better dimensional stability than Nylon. It absorbs less moisture and maintains its shape more consistently in normal working environments. For parts with tight tolerances, Delrin is often the safer choice.

Nylon, on the other hand, is more sensitive to humidity. When exposed to moisture, Nylon can absorb water and expand slightly. This may not be a serious problem for larger parts or general industrial components, but it can be a concern for precision parts.

If your project requires stable dimensions, accurate assembly, or tight tolerance control, Delrin is usually better.

Key Difference 2: Moisture Absorption

Moisture absorption is a major difference between Delrin and Nylon.

Delrin has low moisture absorption, so it performs well in environments where size stability is important. It is suitable for precision components used in equipment, electronics, automation systems, and mechanical assemblies.

Nylon absorbs more moisture from the surrounding environment. This can improve its toughness in some cases, but it may also lead to dimensional changes. In humid environments or applications involving water exposure, Nylon parts may swell, which can affect fit and function.

For wet or humid applications, the material choice depends on the part design and tolerance requirements. If precision is more important, Delrin may be preferred. If toughness and impact resistance are more important, Nylon may still be a good option.

Key Difference 3: Wear Resistance and Friction

Both Delrin and Nylon provide good wear resistance, but their performance differs depending on the application.

Delrin has a naturally low coefficient of friction. This makes it excellent for sliding parts, gears, rollers, and components that need smooth movement with reduced friction. It is often used when low friction and quiet operation are important.

Nylon also has good wear resistance and is suitable for bearings, bushings, wheels, and wear pads. It performs well under repeated movement and load. In some heavy-duty applications, Nylon can provide good durability due to its toughness.

If the part requires smooth sliding, precise movement, and low friction, Delrin is often better. If the part needs strong wear resistance with higher toughness, Nylon may be more suitable.

Key Difference 4: Strength and Toughness

Nylon is generally known for its toughness and impact resistance. It can handle shock loads and repeated stress better in many applications. This makes it useful for industrial parts that may experience vibration, impact, or heavy-duty use.

Delrin is strong and stiff, but it is usually less tough than Nylon under impact. Its advantage is more focused on rigidity, accuracy, and low-friction performance.

For parts that require high stiffness and precision, Delrin is a strong choice. For parts that need impact resistance and durability under dynamic loading, Nylon may be better.

Key Difference 5: Machinability

Both Delrin and Nylon can be CNC machined, but Delrin is generally easier to machine with high precision.

Delrin cuts cleanly, produces a good surface finish, and supports tighter tolerance control. This makes it ideal for precision CNC plastic parts, small mechanical components, and parts with complex geometry.

Nylon can also be machined successfully, but it is more flexible and may be more difficult to hold tight tolerances, especially for thin-walled or complex parts. Proper tooling, clamping, cutting parameters, and cooling control are important when machining Nylon.

For precision CNC machining projects, Delrin usually provides better processing stability.

When Should You Choose Delrin?

Delrin is a good choice when your part requires precision, dimensional stability, and smooth movement.

It is commonly used for:

Gears and small transmission parts
Bushings and bearings
Rollers and sliding components
Precision fixtures
Valve and pump components
Electrical insulation parts
Automation equipment components
Low-friction mechanical parts

Delrin is especially suitable for CNC machined plastic parts that require tight tolerances and stable long-term performance.

When Should You Choose Nylon?

Nylon is a good choice when your part needs toughness, impact resistance, and wear resistance.

It is commonly used for:

Industrial wheels and rollers
Wear pads and guide rails
Pulleys and spacers
Bushings and bearings
Mechanical support parts
Heavy-duty plastic components
Parts exposed to repeated stress
General industrial plastic parts

Nylon is often selected for functional parts where durability and strength are more important than extremely tight dimensional control.

Delrin vs Nylon: Which One Is Better?

There is no single answer for every project. The better material depends on the application.

If your part needs high precision, low friction, good surface finish, and low moisture absorption, Delrin is usually the better choice. It is especially suitable for CNC precision plastic parts and mechanical components requiring stable dimensions.

If your part needs toughness, impact resistance, fatigue resistance, and good durability, Nylon may be the better choice. It is suitable for industrial components that need to withstand stress, movement, and wear.

For many customers, the best solution is not simply choosing the “stronger” material, but choosing the material that matches the working environment, load, tolerance, cost target, and assembly requirements.

How KONSTUN Precision Supports CNC Plastic Machining Projects

Shenzhen KONSTUN Precision Technology Co., Ltd. specializes in custom precision parts manufacturing, including CNC plastic parts, CNC metal parts, sheet metal parts, molds, injection molded parts, vacuum casting parts, and 3D Printed Parts.

For CNC plastic machining projects, we help customers evaluate material selection based on part drawings, tolerance requirements, surface finish, application environment, and production volume. Whether your project requires Delrin, Nylon, ABS, PC, acrylic, PTFE, PEEK, or other engineering plastics, our team can provide practical manufacturing suggestions before production.

With advanced CNC machining equipment and strict quality control processes, KONSTUN Precision focuses on producing stable, accurate, and reliable custom parts for global customers.

Conclusion

Delrin and Nylon are both excellent engineering plastics, but they are suitable for different needs. Delrin is better for precision, low friction, dimensional stability, and smooth mechanical movement. Nylon is better for toughness, impact resistance, wear resistance, and heavy-duty industrial use.

Before choosing a material, it is important to consider the actual working environment, tolerance requirements, mechanical load, moisture exposure, and production budget. A reliable CNC machining supplier can help you avoid material selection mistakes and improve the performance of your final product.

For custom CNC plastic machined parts, Shenzhen KONSTUN Precision Technology Co., Ltd. can support your project from material selection to precision manufacturing and final inspection.