POM vs Nylon: Which Engineering Plastic Is Better for Your Application?

POM (Polyoxymethylene, also known as Acetal), and Nylon (usually referring to Polyamide/PA) are both commonly used engineering plastics in industrial fields, widely used in gears, bushings, bearings, rollers, mechanical parts, and structural components. For companies needing to purchase engineering plastics, a common question is: which is better, POM or Nylon?

In reality, there is no single material that is better for all applications. POM is generally more suitable for applications requiring low friction, wear resistance, dimensional stability, and precision machining, while Nylon has advantages in toughness, impact resistance, and structural properties.

Therefore, the choice between POM and Nylon should be based on the working environment, mechanical loads, humidity, friction, temperature, and end-use.

What Is POM?

POM is a high-performance engineering plastic, also known as Acetal. POM possesses high stiffness, excellent dimensional stability, low friction, outstanding wear resistance and excellent machinability.

POM has low moisture absorption, making it particularly advantageous for mechanical parts requiring dimensional accuracy. It is commonly used in the manufacture of gears, bushings, rollers, guide rails, precision mechanical parts, and various custom machined components.

Key Properties of POM

- Low friction

- Excellent wear resistance

- Good dimensional stability

- Low hygroscopicity

- High stiffness

- Good fatigue performance

- Excellent machinability

What Is Nylon?

Nylon is a common engineering plastic, usually referring to polyamide (PA). Common types include PA6, PA66, and various filled and modified nylons.

Compared to POM, Nylon generally has better toughness, impact resistance, and mechanical strength, therefore it is widely used in bearings, gears, rollers, structural components, and wear-resistant mechanical parts.

It is important to note that the properties vary significantly between different Nylon types and modified formulations. Therefore, specific applications should be evaluated based on the technical data for the corresponding material grade.

Key Properties of Nylon

- High Strength

- Excellent Toughness

- Good Wear Resistance

- Good Impact Resistance

- Good Fatigue Resistance

POM vs Nylon: Key Differences

POM vs Nylon: Dimensional Stability

If a project requires high dimensional accuracy, POM is generally a preferred material.

A key characteristic of nylon is its relatively high hygroscopicity. When the material is exposed to humid environments or comes into contact with moisture for extended periods, its dimensional and mechanical properties may change.

POM typically has lower hygroscopicity, making it more suitable for precision mechanical parts, precision gears, bushings, guide components and parts requiring high dimensional tolerance requirements.

POM usually offers advantages for products that require good dimensional stability in environments with significant humidity variations.

POM vs Nylon: Moisture Absorption

A key difference between POM and Nylon is their hygroscopicity.

Nylon absorbs moisture from the environment, which can affect the material's dimensions, weight, and some mechanical properties. Therefore, this factor needs special consideration in high-humidity environments or applications requiring high dimensional accuracy.

In contrast, POM has lower hygroscopicity, making it generally more suitable for applications requiring more stable dimensions.

POM vs Nylon: Friction and Wear Resistance

POM has low friction and excellent wear resistance, making it frequently used in mechanical components requiring sliding or movement, such as gears, bushings, rollers, guide rails, sliders, and conveyor parts.

Nylon also offers good wear resistance, along with good toughness and impact resistance.

Therefore, if low friction and dimensional stability are the primary considerations, POM is generally more advantageous, while if both toughness and impact resistance are required, Nylon may be more suitable.

POM vs Nylon: Machinability

POM typically possesses excellent machinability, making it ideal for turning, milling, drilling, and CNC precision machining.

Therefore, POM is commonly used to manufacture precision gears, sleeves, shims, rollers, guides and custom mechanical parts.

For projects requiring the machining of complex mechanical parts from POM sheets, POM rods, or other semi-finished plastic products, POM is a very common choice.

POM vs Nylon: Chemical Resistance

Chemical resistance is another important factor when selecting between POM and Nylon, especially for industrial components exposed to oils, fuels, solvents, cleaning agents, and other chemicals.

Although both POM and Nylon offer good chemical resistance compared with many general-purpose plastics, their performance differs depending on the chemical type, exposure time, temperature, and material grade.

POM vs Nylon: Temperature Resistance

Temperature resistance is an important consideration when choosing engineering plastics for industrial applications.

Both POM and Nylon can operate in moderate-temperature environments, but Nylon generally has better high-temperature capability, while POM offers better dimensional stability during temperature changes.

POM vs Nylon: Which Is Better for Gears?

Both POM and Nylon can be used for manufacturing gears, but their applications are different.

POM is generally more suitable for precision gears, low-friction gears, gears requiring high dimensional stability, and high-speed moving parts.

However, Nylon is typically more suitable for gears requiring high impact resistance, mechanical parts requiring good toughness, and some structural gear applications.

Therefore, if precision, low friction, and dimensional stability are the priorities, POM should be considered first, while if toughness and impact resistance are the priorities, Nylon should be considered.

POM vs Nylon: Which Is Better for Bushings and Bearings?

For bearings and bushings, material selection typically depends on friction, wear resistance, load, speed, and the operating environment.

POM is characterized by low friction, low moisture absorption, and good dimensional stability, making it suitable for precision bushings and sliding components.

Nylon, on the other hand, offers good toughness and impact resistance, so it can also be used for bearings, bushings, and other wear-resistant components.

POM vs Nylon: Which One Should You Choose?

POM vs Nylon: Quick Comparison

Conclusion

Both POM and Nylon are excellent engineering plastics, but their applications differ.

If your project prioritizes low friction, wear resistance, dimensional stability, low moisture absorption, and precision machining, POM is generally a more suitable choice.

If your project pays more attention to toughness, impact resistance, and structural properties, Nylon may be more suitable.

The final material selection should be based on specific loads, speeds, temperatures, humidity, chemical environments, and processing methods. For industrial procurement projects, it is recommended to choose the appropriate material grade based on the actual application, rather than simply choosing based on the material name.

FAQ

1. Is POM better than Nylon?

There's no absolute better or worse. POM generally has advantages in low friction, dimensional stability, low moisture absorption, and precision machining, while Nylon is usually superior in terms of toughness and impact resistance.

2. Is Nylon mechanically stronger than POM?

The "strength" of the two materials needs to be determined based on the specific grade and testing conditions. Generally, Nylon has better toughness and impact resistance, while POM usually has higher stiffness and dimensional stability.

3. Which should gears be made of, POM or Nylon?

If precision, low friction, and dimensional stability are more important for gears, POM is usually a good choice, while if toughness and impact resistance are of greater concern, Nylon can be considered.

4. Which is more wear-resistant, POM or Nylon?

Both have good wear resistance. Actual wear resistance of POM and nylon depends on the material grade, load, speed of movement, temperature, lubrication conditions, and mating materials.

5. Which has better dimensional stability, POM or Nylon?

Generally, POM has better dimensional stability, especially in environments with significant humidity variations, because POM is typically less hygroscopic than Nylon.

6. Is POM easier to machine than Nylon?

Normally, POM has excellent machinability and is well-suited for turning, milling, drilling, and CNC machining, making it widely used in the machining of precision plastic parts.