POM vs PA6 is a common engineering plastic comparison because both materials are widely used for gears, bushings, bearings, sliding parts, housings, and CNC machined components. POM is usually selected for low friction, dimensional stability, wear resistance, and clean machining, while PA6 is chosen for toughness, impact resistance, fatigue performance, and cost-effective mechanical parts.
In this guide, we compare POM vs PA6 by material names, mechanical properties, friction and wear behavior, moisture absorption, dimensional stability, thermal and electrical properties, machinability, applications, cost, and material selection rules.
What Is POM?
POM is an engineering thermoplastic known for low friction, high stiffness, good wear resistance, and excellent dimensional stability. Its full name is polyoxymethylene, and it is often used when a plastic part must move smoothly, hold tight dimensions, and resist repeated mechanical contact.
POM is commonly used in gears, bearings, bushings, rollers, sliding blocks, pump parts, valve components, precision fixtures, and machined mechanical parts. It is especially useful when the design needs a plastic material that behaves predictably under dry sliding and moderate mechanical load.
Compared with PA6, POM absorbs much less moisture and is more dimensionally stable in humid environments. This makes it a strong choice for precision CNC machined parts, small mechanisms, and assemblies where fit and movement must remain consistent.
Key Properties of POM
The key properties of POM are low friction, high stiffness, good wear resistance, low moisture absorption, and strong dimensional stability. These properties make it one of the most practical engineering plastics for precision moving parts.
Common advantages of POM include:
- Low coefficient of friction
- Good wear resistance
- High stiffness and hardness
- Low moisture absorption
- Good dimensional stability
- Clean CNC machinability
- Good fatigue performance in moving parts
- Suitable for gears, bushings, and sliding components
POM is not usually chosen for very high-temperature environments or applications requiring strong chemical resistance to aggressive acids or oxidizers. Its main value is stable mechanical performance, smooth movement, and predictable machining behavior.
What Is PA6?
PA6 is an engineering thermoplastic known for toughness, impact resistance, fatigue strength, and good mechanical performance. Its full name is polyamide 6, and it belongs to the nylon family.
PA6 is commonly used in automotive parts, industrial components, housings, clips, gears, wheels, rollers, electrical parts, and general mechanical components. It is often selected when the part needs toughness and resistance to dynamic load rather than maximum dimensional stability.
Compared with POM, PA6 absorbs more moisture from the environment. Moisture can improve toughness in some cases, but it can also reduce stiffness, change dimensions, and affect tight-tolerance assemblies.
Key Properties of PA6
The key properties of PA6 are toughness, impact resistance, fatigue performance, good wear behavior, and practical cost. These properties make PA6 useful for parts that experience shock, vibration, or repeated load.
Common advantages of PA6 include:
- Good toughness
- Good impact resistance
- Good fatigue resistance
- Good mechanical strength
- Good wear resistance in many applications
- Suitable for molded and machined parts
- Cost-effective for mechanical components
- Available in filled and modified grades
The main limitation of PA6 is moisture absorption. Water uptake can change dimensions and mechanical properties, which must be considered for precision parts, humid environments, and assemblies with tight fits.
POM vs PA6: Quick Comparison
POM vs PA6 can be summarized as dimensional stability versus toughness. POM provides lower friction, better dimensional stability, and cleaner machining. PA6 provides better toughness, impact resistance, and cost-effective mechanical performance.
| Property Focus | POM | PA6 |
| Main advantage | Low friction and stability | Toughness and impact resistance |
| Stiffness | Higher and more stable | Good, but moisture-dependent |
| Wear resistance | Very good | Good |
| Friction | Lower | Higher than POM |
| Moisture absorption | Low | High |
| Dimensional stability | Better | More affected by humidity |
| Impact resistance | Good | Better |
| Machinability | Excellent | Good, but more flexible |
| Cost | Moderate | Often cost-effective |
| Best use | Precision sliding parts | Tough mechanical parts |
Strength and Rigidity
POM is generally more rigid and dimensionally stable than PA6, while PA6 can provide strong mechanical performance with better toughness. POM keeps its stiffness more consistently because it absorbs less moisture.
In dry conditions, PA6 can show good tensile strength, but moisture can reduce stiffness and change mechanical behavior. For precision mechanisms, POM is often more predictable. For parts facing impact or vibration, PA6 may be more suitable.
Wear Resistance and Friction
POM usually has better low-friction behavior than PA6, which makes it suitable for gears, bushings, sliding blocks, and moving mechanical parts. Its surface behavior helps reduce noise, resistance, and stick-slip in many dry-running applications.
PA6 also has good wear resistance, especially in modified or lubricated grades. However, for dry transmission and smooth movement, POM is often easier to design because of its lower friction and better dimensional consistency.
Moisture Absorption
PA6 absorbs much more moisture than POM, and this is one of the most important differences between the two materials. Moisture can cause PA6 to swell, reduce stiffness, and change part dimensions.
POM has low moisture absorption, so it maintains size and mechanical behavior more consistently in normal humidity. This makes POM better for tight-tolerance parts, precision gears, and assemblies where clearance matters.
Dimensional Stability
POM has better dimensional stability than PA6 because it absorbs less water and has higher stiffness in typical use. It is easier to control in CNC machining and more reliable for parts that require stable fit.
PA6 can change dimensions after machining if moisture content changes. This does not mean PA6 is unsuitable, but designers should allow realistic tolerances and consider conditioning when the part works in humid environments.
Thermal Properties
PA6 generally performs better than POM in some heat-related applications, especially when reinforced grades are used. POM provides good mechanical performance at moderate temperatures, but it has clearer limits in long-term high-temperature service.
For thermal selection, engineers should consider both temperature and load. POM may be better for stable precision movement at moderate temperatures, while PA6 may be better when toughness and heat resistance are more important than dimensional precision.
Electrical Properties
POM and PA6 both offer useful electrical insulation, but POM is usually more stable in humid conditions because it absorbs less moisture. Moisture can reduce the electrical insulation performance of PA6.
For electrical parts that require stable insulation and dimensional control, POM may be easier to manage. PA6 can still be used in electrical components, especially when toughness, impact resistance, or molded design flexibility is required.
Fire Behavior
Neither standard POM nor standard PA6 should be assumed to be flame-retardant without checking the exact grade. Fire behavior depends strongly on formulation, fillers, additives, thickness, and certification.
POM can burn and may release irritating decomposition products under improper thermal conditions. PA6 can also burn unless flame-retardant grades are selected. For electrical or regulated applications, UL rating and supplier data should be confirmed before production.
Cost and Availability
PA6 is often more cost-effective than POM for general mechanical parts, while POM may reduce machining and quality risks for precision components. The better economic choice depends on the part function, tolerance, volume, and failure risk.
POM is widely available in rods, sheets, and plates for CNC machining. PA6 is also widely available, including extruded, cast, filled, and modified grades. Stock form and grade should be confirmed early for urgent projects.
POM vs PA6: Mechanical Properties Comparison
POM and PA6 both offer useful mechanical performance, but POM is better for stiffness and dimensional control, while PA6 is better for toughness and impact resistance. This difference guides most engineering material choices.
Tensile Strength and Toughness
PA6 usually provides good tensile strength and better toughness, while POM provides strong stiffness and more stable mechanical behavior. PA6 can absorb impact energy better, especially in applications with sudden load or vibration.
POM is less flexible but more precise. It is better for parts where stiffness, surface finish, and dimensional control matter more than impact absorption. The best choice depends on whether the part is expected to flex or stay rigid.
Impact Resistance
PA6 generally has better impact resistance than POM, especially when conditioned with moisture. This makes PA6 useful for clips, housings, covers, and parts that may experience shock or assembly impact.
POM still offers good toughness for many mechanical parts, but it is normally selected more for precision movement and stability. For impact-heavy applications, PA6 or modified nylon grades should be reviewed.
Creep Resistance and Load-Bearing Performance
POM usually has better creep resistance and dimensional stability under moderate load than PA6, especially in humid environments. This helps POM maintain fit and function in gears, bushings, and precision assemblies.
PA6 can carry load well, but its creep and stiffness can be affected by moisture and temperature. For long-term load-bearing parts, designers should check actual working conditions instead of relying only on dry-state datasheet values.
POM vs PA6: Friction and Wear Performance
POM usually performs better than PA6 in low-friction and dry sliding applications. PA6 can wear well in certain grades, but its friction and moisture sensitivity make it less predictable in precision sliding systems.
Low-Friction Performance of POM
POM has low friction and good self-lubricating behavior, which makes it a strong choice for gears, sliding rails, rollers, and bushings. It can help reduce noise and movement resistance in dry-running mechanisms.
Because POM also holds dimensions well, gear tooth geometry and sliding clearance remain more stable over time. This is one reason POM is commonly used for precision plastic gears and small moving assemblies.
Wear Behavior of PA6
PA6 has good wear behavior, especially in lubricated applications or modified grades. It can work well in rollers, wheels, bushings, and mechanical parts where toughness is important.
However, PA6 may absorb moisture and become less stiff, which can affect contact pressure, clearance, and wear pattern. For dry precision transmission, POM is often the more predictable option.
Dry Transmission and Sliding Applications
POM is usually preferred for dry transmission and sliding applications because it combines low friction, low moisture absorption, and good dimensional stability. It is commonly used for gears, guide parts, and sliding blocks.
PA6 can be used when higher toughness or impact absorption is required. If the application involves shock load, vibration, or less critical clearance, PA6 may still perform well.
Tribological Selection Tips
Tribological selection should consider friction coefficient, wear rate, contact pressure, sliding speed, lubrication, temperature, and moisture exposure. A material that performs well in one sliding system may not work in another.
Choose POM for stable dry sliding and precision movement. Choose PA6 when toughness, fatigue resistance, or impact absorption is more important. For severe wear conditions, filled or lubricated grades of both materials should be compared.
POM vs PA6: Moisture Absorption and Dimensional Stability
Moisture absorption is one of the biggest differences between POM and PA6. POM absorbs little moisture and holds dimensions well, while PA6 absorbs water and may swell or change mechanical behavior.
Why PA6 Absorbs More Moisture
PA6 absorbs more moisture because its polyamide molecular structure attracts water. This moisture can increase toughness but reduce stiffness and cause dimensional change.
In practical use, PA6 parts may change size after machining, storage, or service exposure. Designers should consider humidity, water contact, and conditioning when specifying PA6 for precision parts.
Why POM Holds Dimensions Better
POM holds dimensions better because it has much lower moisture absorption than PA6. This makes it more predictable in normal humidity and better for parts that need stable clearance, alignment, or fit.
For CNC machined components, POM is often preferred when tight tolerances, flatness, roundness, and repeatable assembly are important. It reduces the risk of swelling-related interference or looseness.
Tolerance Control for CNC Machined Parts
Tolerance control is usually easier with POM than with PA6 because POM is stiffer and less affected by moisture. It can hold machined features more consistently after cutting and inspection.
PA6 can still be CNC machined accurately, but tolerance planning should account for moisture, internal stress, and part geometry. For thin walls, press fits, or tight holes, realistic tolerance and material conditioning are important.
POM vs PA6: Thermal and Electrical Properties
POM and PA6 both provide useful thermal and electrical performance, but PA6 is often stronger in heat-related toughness, while POM is more stable in moisture-sensitive electrical and dimensional applications.
Heat Resistance Comparison
PA6 can offer good heat resistance, especially in reinforced grades, while POM is better suited to moderate-temperature mechanical precision parts. Standard POM may lose performance if used too close to its thermal limits for long periods.
If the part works near engines, heated equipment, or continuous elevated temperatures, PA6 or reinforced PA grades may be considered. If the main need is low-friction precision movement at moderate temperature, POM is often better.
Electrical Insulation Comparison
POM and PA6 can both be used for electrical insulation, but POM generally provides more stable insulation performance in humid conditions. PA6 moisture absorption can affect dielectric behavior and dimensional fit.
For connectors, supports, spacers, and insulating components, the final choice should consider humidity, mechanical load, heat, and flame requirements. Flame-retardant grades may be required for electrical assemblies.
Performance Limits in High-Temperature Applications
Both POM and PA6 have performance limits in high-temperature applications. POM is not ideal for prolonged high-temperature service, while PA6 may lose stiffness or change dimensions under moisture and heat.
For demanding heat environments, designers should compare reinforced grades, PA66, PBT, PPS, or higher-performance plastics. Material selection should be based on continuous temperature, load, exposure time, and safety requirements.
POM vs PA6: Machinability and Manufacturing
POM is usually easier to machine cleanly and hold dimensionally stable, while PA6 is machinable but more affected by flexibility, moisture, and internal stress. Both materials can be CNC machined, but they require different manufacturing controls.
CNC Machining POM
CNC machining POM is practical for precision parts because the material cuts cleanly, holds dimensions well, and provides a good machined surface. It is suitable for milled plates, gears, bushings, rollers, spacers, fixtures, and complex mechanical parts.
POM can be processed by CNC milling, CNC turning, drilling, tapping, boring, and profiling. Sharp tools, stable clamping, moderate cutting parameters, and burr control help maintain surface finish and tolerance.
Because POM is dimensionally stable and low-friction, it is often preferred for parts that require sliding clearance, gear tooth accuracy, or repeatable assembly. For tight-tolerance parts, stress relief and proper stock selection may still be needed.
CNC Machining PA6
CNC machining PA6 is possible for functional components, but dimensional control can be more challenging than with POM. PA6 is tougher and more elastic, so it may deflect during cutting or change dimension with moisture.
PA6 can be machined by CNC milling, CNC turning, drilling, boring, threading, and contour machining. Fixturing should avoid excessive clamping pressure, especially on thin-wall or flexible features.
For precision PA6 parts, moisture conditioning, sharp tools, controlled heat, and realistic tolerances are important. If the part must hold tight dimensions in humid service, POM may be the safer choice.
Laser Cutting of POM and PA6
POM and PA6 can both be considered for laser cutting in sheet form, but POM often gives cleaner edges and more predictable results. PA6 can be more difficult depending on thickness, grade, and cutting conditions.
Laser cutting is useful for flat profiles, templates, small plates, and simple geometry. However, for precision 3D parts, holes, threads, pockets, or tight-fit features, CNC machining is usually more suitable.
Edge Quality and Melt Marks
POM usually produces neater edges in many cutting processes, while PA6 may show more melting, edge variation, or surface effects depending on process conditions. Edge quality matters when the part is visible or must fit with other components.
For CNC machining, both materials can achieve good edge quality with sharp tools and correct parameters. Deburring should be controlled carefully, especially for small gears, slots, and thin features.
Thickness Tolerance and Production Stability
Production stability depends on material stock, thickness tolerance, moisture condition, internal stress, and machining process. POM generally provides more predictable dimensional behavior across batches.
PA6 stock may require more attention to moisture and storage conditions. For large panels, thin parts, or tight-tolerance assemblies, material conditioning and inspection planning should be included before production.
Typical Applications of POM and PA6
POM and PA6 are used in different applications because POM is better for stable low-friction movement, while PA6 is better for tough and impact-resistant mechanical parts. Both materials are valuable engineering plastics, but they should not be treated as interchangeable.
POM Applications
POM is commonly used for gears, bearings, bushings, rollers, sliding blocks, conveyor components, pump parts, valve parts, fasteners, clips, housings, and precision CNC machined components.
It is often selected when the part must resist wear, move smoothly, and keep dimensions stable. POM is especially useful for small mechanical assemblies where clearance and repeatability matter.
PA6 Applications
PA6 is commonly used for automotive components, wheels, rollers, housings, clips, cable ties, electrical supports, machine parts, and general industrial components. It is useful where toughness and impact resistance are more important than maximum dimensional stability.
PA6 can also be modified with glass fiber, oil, or other fillers to improve stiffness, wear resistance, or thermal behavior. Grade selection should match the actual load and environment.
Gears, Bearings, Bushings, and Sliding Parts
For gears, bearings, bushings, and sliding parts, POM is often preferred when low friction, quiet operation, and dimensional accuracy are required. It works well in dry-running and moderate-load mechanisms.
PA6 can be used for larger or tougher parts that experience shock, vibration, or impact. In lubricated or filled-grade applications, PA6 may offer strong wear performance and good service life.
Automotive and Industrial Components
In automotive and industrial components, POM is used where precision, wear resistance, and stable movement are important. Typical examples include clips, fuel system parts, gears, rollers, and sliding elements.
PA6 is used where toughness, fatigue resistance, and cost-effective strength are required. It is common in housings, brackets, protective parts, and components exposed to mechanical shock.
Electrical and Consumer Product Parts
For electrical and consumer product parts, POM is useful when stable dimensions, good surface quality, and low friction are needed. It can be used in switches, small mechanisms, housings, and moving assemblies.
PA6 is useful for durable housings, clips, supports, and parts that require impact resistance. If the component has flame or electrical safety requirements, the exact grade and certification must be confirmed.
POM vs PA6: Advantages and Disadvantages
POM and PA6 both have advantages and disadvantages, and neither material is better for every project. POM is stronger in dimensional stability and friction control, while PA6 is stronger in toughness and impact performance.
Advantages of POM
The main advantages of POM are low friction, high stiffness, wear resistance, low moisture absorption, and clean machinability. These benefits make it excellent for precision mechanical parts.
POM is especially useful when the design requires stable dimensions, smooth sliding, repeatable fit, and good surface finish. It is often the better choice for CNC machined gears, bushings, rollers, and sliding parts.
Disadvantages of POM
The main disadvantages of POM are limited long-term high-temperature performance, sensitivity to strong acids or oxidizers, and fire behavior concerns in some applications. It may not be suitable for all chemical or high-heat environments.
POM also has lower impact toughness than PA6 in many situations. If the part must absorb shock or operate in severe impact conditions, PA6 or modified grades may be more suitable.
Advantages of PA6
The main advantages of PA6 are toughness, impact resistance, fatigue performance, good mechanical strength, and cost-effectiveness. It is useful for durable parts that must handle vibration, shock, or repeated loading.
PA6 also offers flexibility in modification. Glass-filled, oil-filled, and other reinforced grades can improve stiffness, wear resistance, and temperature capability for specific applications.
Disadvantages of PA6
The main disadvantage of PA6 is moisture absorption. Water uptake can change dimensions, reduce stiffness, and affect tolerance stability, which can be a problem for precision assemblies.
PA6 may also be more difficult to control in CNC machining when tight tolerances, thin walls, or stable long-term dimensions are required. For these conditions, POM is often easier to manage.
POM vs PA6: Cost, Delivery, and Production Considerations
Cost, delivery, and production should be considered because material price alone does not decide the best plastic. Machining time, scrap risk, tolerance control, stock availability, and service life also affect total cost.
Material Cost Comparison
PA6 is often cost-effective for general mechanical parts, while POM may provide better value for precision parts because it reduces dimensional risk and machining uncertainty. The price difference depends on grade, stock form, quantity, and supplier.
Glass-filled or modified PA6 may cost more than standard PA6. POM-C, POM-H, and branded acetal grades may also vary in cost. Final selection should compare performance and production risk, not only raw material price.
Machining Cost and Scrap Risk
POM can reduce machining cost and scrap risk for precision parts because it cuts cleanly and holds dimensions well. It is often easier to inspect and assemble after machining.
PA6 can still be economical, but moisture movement, elastic deflection, and internal stress may increase inspection needs for tight-tolerance parts. For simple robust parts, PA6 can remain a cost-effective choice.
Stock Availability and Lead Time
POM and PA6 are both widely available in rods, plates, sheets, and molded stock, but exact grade, color, thickness, and certification can affect lead time. POM is commonly stocked for machining because of its dimensional stability and broad industrial use.
PA6 is also widely available, especially in standard and reinforced grades. For urgent projects, stock form and moisture condition should be confirmed early to avoid delays or machining changes.
How to Choose Between POM and PA6?
Choose POM when dimensional stability, low friction, and machining accuracy are the main requirements. Choose PA6 when toughness, impact resistance, and cost-effective mechanical strength are more important.
Choose POM for Dimensional Stability and Low Friction
POM is the better choice when the part needs stable dimensions, smooth sliding movement, and clean machining. It is especially suitable for precision gears, bushings, rollers, spacers, sliding rails, and CNC machined mechanical parts.
Choose POM when the project needs:
- Low friction
- Good wear resistance
- High dimensional stability
- Low moisture absorption
- Clean CNC machining
- Stable gear or sliding movement
- Tight tolerance control
- Predictable assembly fit
Choose PA6 for Toughness and Impact Resistance
PA6 is the better choice when the part must absorb impact, handle vibration, or provide tough mechanical performance at a reasonable cost. It is suitable for automotive parts, rollers, housings, clips, wheels, and industrial components.
Choose PA6 when the project needs:
- High toughness
- Good impact resistance
- Good fatigue performance
- Cost-effective strength
- Vibration resistance
- General mechanical durability
- Reinforced grade options
- Less critical dimensional tolerance
Decision Summary for Engineering Parts
The decision is straightforward when the main performance risk is clear. If the risk is swelling, friction, or tolerance drift, choose POM. If the risk is impact, vibration, or shock failure, choose PA6.
| Requirement | Recommended Material |
| Better dimensional stability | POM |
| Lower moisture absorption | POM |
| Lower friction | POM |
| Cleaner CNC machining | POM |
| Precision gears | POM |
| Better toughness | PA6 |
| Better impact resistance | PA6 |
| Cost-effective mechanical parts | PA6 |
| Vibration-prone parts | PA6 |
| Humid tight-tolerance parts | POM |
FAQs
Is POM Better Than PA6?
POM is better than PA6 when the part needs low friction, dimensional stability, low moisture absorption, and tight-tolerance CNC machining. PA6 is better when the part needs toughness, impact resistance, fatigue performance, and cost-effective mechanical strength. In simple terms, choose POM for precision sliding parts and choose PA6 for tough mechanical parts.
Is POM the Same as Nylon?
No, POM is not the same as nylon. POM is polyoxymethylene, also called acetal or polyacetal. Nylon is a polyamide family that includes PA6 and PA66. POM absorbs less moisture and holds dimensions better, while nylon usually offers better toughness and impact resistance. The correct choice depends on tolerance, load, friction, and environment.
Which Is Better for Gears, POM or PA6?
POM is usually better for precision gears because it offers low friction, good wear resistance, low moisture absorption, and stable tooth geometry. PA6 can be used for gears when toughness, impact resistance, or vibration absorption is more important. For dry-running, quiet, and dimensionally stable gears, POM is often the preferred material.
What Is The Difference Between PA6 And POM?
The main difference is moisture absorption and stability. POM absorbs less moisture, usually below 0.5%, so it holds tighter dimensions and works well for gears and sliding parts. PA6 absorbs more water, which improves toughness but may cause swelling. Choose POM for precision, choose PA6 for impact resistance.
Is POM Plastic Strong?
Yes, POM is strong for engineering plastic parts. Its tensile strength is commonly around 60–70 MPa, depending on grade. It offers good stiffness, wear resistance, and fatigue performance, making it suitable for gears, bushings, rollers, and CNC machined parts. However, it is not ideal for strong acids or very high temperatures.
Conclusion
POM and PA6 are both useful engineering plastics, but they are designed for different manufacturing goals. POM is better for low friction, dimensional stability, wear resistance, and precision CNC machined parts. PA6 is better for toughness, impact resistance, fatigue performance, and cost-effective mechanical components. The right choice depends on whether the part needs stable precision or flexible durability.
At TiRapid, we provide precision CNC machining services for custom plastic components across multiple industries. If you are comparing POM vs PA6 for a machined part, upload your drawing or share your material requirements to get a tailored manufacturing solution.
