PA66 and POM are engineering plastics used for wear-resistant profiles, guides, rails, spacers, and sliding components. PA66 generally offers higher toughness and fatigue resistance, while POM is often preferred for low friction, low moisture absorption, and stable dimensions.
Lingo Rubber Plastic produces custom plastic parts through extrusion molding and other manufacturing processes. When PA66 or POM cannot meet the operating conditions, materials such as PEEK, PEI, PPS, UHMWPE, and PAI may provide better thermal, chemical, wear, or structural performance.
PA66 and POM at a glance
| Selection factor | PA66 | POM |
|---|---|---|
| Strength and toughness | Strong, tough, and fatigue resistant | Rigid with good mechanical stability |
| Wear and friction | Good wear resistance; friction depends on grade and lubrication | Low friction and good sliding behavior |
| Moisture absorption | Higher; dimensions and properties can change with moisture | Low; dimensions remain more stable in humid conditions |
| Temperature capability | Good for many mechanical applications | Good for moderate service temperatures |
| Machinability | Good, but moisture conditioning matters | Excellent dimensional control during machining |
| Typical profile use | Structural guides, protective rails, wear parts, clips | Slide rails, precision guides, low-friction profiles, gears |
When PA66 is the better choice
Choose PA66 when the profile needs toughness, fatigue resistance, impact performance, and mechanical strength. It suits guide rails, structural strips, protective profiles, clips, spacers, and parts exposed to repeated loading. Reinforced grades can add stiffness when the geometry and extrusion process support them.
The main design issue is moisture absorption. PA66 can absorb moisture from the environment, which may change dimensions, stiffness, and impact behavior. If a profile must fit a narrow channel or maintain a tight gap, define the humidity condition used for inspection and consider how the part will behave after conditioning in service.
When POM is the better choice
Choose POM when low friction, smooth movement, and dimensional stability matter more than maximum toughness. It is widely used for slide rails, guide profiles, precision spacers, and parts that move against metal or another plastic.
POM absorbs much less moisture than PA66, so it often maintains dimensions more consistently in changing humidity. It also machines cleanly when holes, slots, or end features must be added after extrusion. POM is not the first choice for every chemical or high-temperature environment, so confirm exposure conditions before selecting a grade.
PA66 vs POM for wear-resistant profiles
Wear depends on load, speed, mating surface, lubrication, temperature, debris, and alignment. POM often gives lower friction in dry sliding, while PA66 may handle impact and repeated stress better when toughness matters more than precision movement.
For a guide or wear strip, test the actual profile against the real mating material. A dimensional inspection can confirm the drawing, but it cannot show noise, drag, abrasion, deformation under load, or the effect of heat generated during movement.
Moisture and dimensional stability
Moisture is one of the clearest differences between PA66 and POM. PA66 changes as it absorbs moisture, while POM remains comparatively stable. This does not make PA66 unsuitable. It means the drawing, tolerance, storage condition, and inspection method must account for the material behavior.
If the assembly has a press fit, snap fit, narrow sliding clearance, or sealing interface, discuss the expected humidity range with the supplier. For POM, thermal expansion and process shrinkage still matter, even though moisture absorption is lower.
Temperature and chemical exposure
Both materials serve many industrial environments, but neither covers every chemical or temperature requirement. Check grade-specific data for continuous temperature, short-term peaks, fuels, oils, cleaners, acids, alkalis, and steam.
If the profile faces sustained high heat, aggressive chemicals, sterilization, or demanding electrical requirements, a higher-performance polymer may be more suitable.
Alternatives for more demanding applications
| Material | Why you might choose it | Main trade-off |
|---|---|---|
| PEEK | High temperature capability, chemical resistance, wear performance, and mechanical strength | High material and processing cost |
| PEI | High heat resistance, stiffness, dimensional stability, and electrical performance | Cost and chemical limitations must be reviewed |
| PPS | Heat resistance, chemical resistance, dimensional stability, and low moisture absorption | Can be more brittle than PA66 or POM depending on grade |
| UHMWPE | Very low friction, abrasion resistance, and impact performance | Lower stiffness and more difficult tight-tolerance extrusion |
| PAI | High strength, wear resistance, and performance at elevated temperature | Very high cost and specialized processing |
PEEK
PEEK is a strong candidate when PA66 and POM cannot meet temperature, chemical, or wear requirements. It suits demanding guides, seals, and structural profiles, but its higher material and processing cost should be justified by the operating conditions.
PEI
PEI offers heat resistance, stiffness, dimensional stability, and useful electrical properties. It may suit insulating or structural profiles that need better thermal performance than PA66 or POM.
PPS
PPS combines heat resistance, chemical resistance, low moisture absorption, and dimensional stability. Because some grades are brittle, profile radii and wall transitions need careful design.
UHMWPE
UHMWPE is often selected for wear strips, conveyor guides, liners, and low-friction profiles. It offers excellent abrasion and impact resistance, but it is less stiff than PA66, POM, PEEK, PPS, or PAI. Tight tolerances and complex profile geometry may also be more difficult to maintain.
PAI
PAI provides high strength, wear resistance, and elevated-temperature performance. Its cost and specialized processing make early supplier review essential.
Match the material to the application
Start with the working conditions rather than choosing the strongest or most expensive material. Define load, movement speed, friction, mating surface, temperature, moisture, chemicals, UV exposure, electrical needs, allowable wear, expected service life, and target cost. Then compare grades that can be extruded into the required cross-section.
The profile geometry also affects the choice. A material may look suitable on a data sheet but perform poorly in a thin fin, deep channel, hollow profile, or tight snap fit. Share the CAD drawing and assembly context before finalizing the resin.
Quotation checklist for engineering plastic profiles
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Provide the 2D profile cross-section, 3D CAD model, units, revision, and cut length.
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Describe the application, load, movement, friction, temperature, moisture, and chemical exposure.
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Identify critical tolerances, straightness, twist, surface, color, and assembly requirements.
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State whether PA66, POM, or another material is preferred and whether the grade must be reinforced or modified.
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List secondary cutting, drilling, punching, CNC machining, printing, or assembly requirements.
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Provide prototype quantity, annual volume, PPAP needs, inspection plan, packaging, and delivery schedule.
How Lingo supports material selection and production
Lingo Rubber Plastic supports CAD-file quotation, material selection, extrusion molding, CNC machining, injection molding, stamping, PVC dipping, and surface finishing for non-standard plastic parts. The company follows customer drawing requirements or industry-standard tolerances, offers PPAP on request, and provides tooling, sample, and production support.
Use first-article samples to confirm fit, sliding behavior, surface quality, straightness, cut length, and performance in the real assembly. For wear applications, run the part against the actual mating surface under expected load and speed before approving volume production.
Is PA66 more wear resistant than POM?
Both materials can provide good wear resistance. POM often has lower friction in dry sliding applications, while PA66 may offer better toughness and fatigue performance. The better option depends on load, speed, mating surface, lubrication, temperature, and moisture.
Which material is more dimensionally stable?
POM is generally more stable in changing humidity because it absorbs less moisture. PA66 can still meet tight functional requirements when moisture conditioning and tolerance planning are handled correctly.
When should PEEK or PPS replace PA66 or POM?
Consider PEEK or PPS when the profile must handle higher continuous temperatures, aggressive chemicals, low moisture absorption, or stricter dimensional requirements than PA66 or POM can provide.
Is UHMWPE suitable for extrusion profiles?
Yes. UHMWPE is widely used for wear strips, guides, and low-friction profiles, but its lower stiffness and processing behavior can limit tight tolerances or complex geometries.
What information is needed for a material recommendation?
Provide the CAD drawing, load, movement, mating surface, temperature, moisture, chemicals, UV exposure, required life, tolerances, quantity, and cost target.
Conclusion
Choose PA66 when toughness, fatigue resistance, and structural performance lead the decision. Choose POM when low friction, clean machining, low moisture absorption, and dimensional stability matter more. For higher heat, chemical exposure, or wear demands, compare PEEK, PEI, PPS, UHMWPE, and PAI instead of forcing PA66 or POM into unsuitable conditions. A CAD review and first-article test will show whether the material and profile geometry work together in the real assembly.
