POM vs PTFE is a comparison that comes up whenever a design team specifies a wear part - a bushing, a slide, a gear or a seal - and has to choose between the material everybody knows (acetal, sold as POM or Delrin-type grades) and the material with the lowest friction on earth (PTFE). The two behave almost opposite in character: POM is a stiff, strong, dimensionally stable engineering plastic, while PTFE is a soft, chemically inert polymer that slides against almost anything. Neither is simply better; the choice depends on load, speed, temperature and whether the joint will ever see lubrication. This guide compares the two on the properties that decide wear life, maps common applications to each material, and shows how to write a specification a supplier can quote against.
POM vs PTFE: Core Property Comparison
The acetal vs PTFE decision starts with the numbers on the datasheet, because the two materials sit at opposite ends of the stiffness-friction trade-off:
| Property | POM (acetal homopolymer/copolymer) | PTFE |
|---|---|---|
| Density | 1.41-1.43 g/cm3 | 2.14-2.20 g/cm3 |
| Tensile strength | 60-70 MPa | 20-30 MPa |
| Flexural modulus | 2.5-3.0 GPa | 0.5-0.7 GPa |
| Coefficient of friction (dry, on steel) | 0.15-0.35 | 0.05-0.15 |
| Max continuous service temperature | ~90-110 C | ~260 C |
| Cold flow / creep under load | Low at room temperature | High; deforms under sustained load |
| Chemical resistance | Good; attacked by strong acids | Near-universal; only molten alkali metals and fluorine attack it |
| Moisture uptake | ~0.2-0.8% | ~0.01% |
| Machining / moulding behaviour | Machines cleanly; moulds well | Machines cleanly; does not melt-process conventionally |
Where POM Wins in Wear Parts
POM is the default when the wear part must also carry load or hold a dimension. Its flexural modulus is several times that of PTFE, so an acetal bushing, gear or guide holds shape under load instead of extruding slowly out of its housing. POM's low moisture uptake means parts keep their fit in humid environments, and its fatigue resistance suits reciprocating motion like conveyor links, hinges and snap features. The classic POM wear applications are gear wheels, pump impellers, valve bodies, slide guides and conveyor components, often running dry or with minimal grease.
Where PTFE Wins
PTFE earns its place wherever friction is the problem rather than load. Its dry coefficient of friction against steel is the lowest of any solid engineering polymer, which makes it the standard for dry-running bearings, plain bearing liners, piston rings and low-torque slides that must not stick on start-up. It also tolerates temperatures that would soften POM entirely and shrugs off nearly every chemical in a processing plant. The catch is creep: an unmodified PTFE bearing under sustained load will slowly cold-flow, which is why PTFE is usually deployed as a thin liner, a filled compound, or an impregnated surface rather than a thick structural section.
Hybrids and Filled Grades
Most real wear-part specifications land between the two extremes, and the market sells hybrids accordingly:
- Filled PTFE - glass, carbon or bronze fillers raise compressive strength and cut wear rate, at the cost of a slightly higher friction coefficient and more abrasion on the mating surface.
- PTFE-lined bearings - a thin PTFE layer bonded to a steel backing gives the low-friction surface a structural home, the standard construction for maintenance-free automotive and agricultural bushings.
- POM-PTFE blends - a small PTFE fraction in acetal drops friction while POM keeps the strength, the common answer for sliding gears and low-torque cams.
- PEEK and other high-temperature polymers - when neither POM's temperature ceiling nor PTFE's creep is acceptable, the specification moves up-market rather than compromising between the two.
Writing the Wear Part Specification
Specify the duty, not just the material. State the load and speed profile, the mating surface material and finish, the temperature range, whether the joint is lubricated, and the required service life. That duty statement lets a supplier choose between virgin POM, a filled PTFE compound or a lined bearing and quote tooling accordingly - and it prevents the classic failure mode where an excellent material was chosen for the wrong reason. Where the part also touches food, remember that food-contact POM grades carry their own compliance requirements, which sit alongside the wear specification rather than replacing it. When the application pushes toward higher structural loads, the PA6 versus PA66 comparison is the usual next step in the material decision tree; more comparisons sit in the material guide section.
Related product categories
The materials and part types discussed above are grouped in our sourcing directory:
