PEEK vs POM — Which Plastic for Your Application?

Properties at a Glance

The table below summarizes the key differences between unfilled PEEK and POM-C (copolymer acetal), the most commonly used grades of each material.

For a deeper look at PEEK’s full property profile, see our PEEK properties article.

Temperature Performance

This is where the gap between PEEK and POM is most dramatic. PEEK can operate continuously at 250°C and withstand short-term peaks up to 300°C without significant degradation. POM, on the other hand, begins to lose mechanical strength above 100°C and starts to degrade noticeably around 120°C.

The rule is simple: if your application sees sustained temperatures above 120°C, POM is off the table. PEEK is one of the few thermoplastics that can handle the thermal demands of automotive turbo systems, oil & gas downhole tools, and industrial oven components.

Mechanical Properties

Both PEEK and POM offer excellent dimensional stability and low creep under sustained load — qualities that make them popular for precision-machined components. POM has a naturally lower coefficient of friction (0.20–0.35 versus 0.35–0.40 for PEEK), making it a better choice for sliding and bearing applications where self-lubrication matters.

PEEK is the stronger material with roughly 50% higher tensile strength, and it retains much more of that strength at elevated temperatures. However, POM’s stiffness and fatigue resistance are more than adequate for the vast majority of mechanical applications at ambient and moderately elevated temperatures.

In terms of wear, unfilled POM often outperforms unfilled PEEK. If wear is the primary concern, glass- or carbon-fiber-filled grades of either material can further improve performance.

Chemical Resistance

PEEK resists virtually all organic and inorganic chemicals. The only notable exception is concentrated sulfuric acid. This makes PEEK an excellent material for chemical processing, semiconductor manufacturing, and analytical equipment.

POM has good resistance to most solvents, fuels, and weak acids, but it is vulnerable to strong mineral acids (such as hydrochloric and nitric acid) and strong oxidizers. In alkaline environments, POM performs well. For applications involving aggressive chemical media, PEEK is the clear and often the only viable choice among unfilled thermoplastics.

Machinability

POM is one of the easiest engineering plastics to machine. It produces clean chips, holds tight tolerances, and yields excellent surface finishes straight off the tool. Standard HSS tooling works well, and cycle times are short. This is one reason POM is so popular for high-volume machined components like gears, bushings, and valve seats.

PEEK can absolutely be machined to high precision, but it demands more from the process. Carbide or diamond tooling is recommended, cutting speeds need to be managed carefully, and the material generates more heat during machining. As a result, machining costs for PEEK parts are significantly higher — not just because of the raw material price, but because of longer cycle times and tooling wear.

Cost Comparison

The price difference between these two materials is substantial. POM typically costs in the range of €5–15/kg, while PEEK commands €80–150/kg depending on the grade and form. When you factor in machining costs, a finished PEEK part can easily be 10–20x more expensive than an equivalent part in POM.

This cost gap means that specifying PEEK where POM would suffice is an expensive mistake. Always validate whether the application truly requires PEEK’s high-temperature or chemical resistance capabilities before committing to it.

When to Choose PEEK

PEEK is the right material when your application involves one or more of the following:

• Continuous operating temperatures above 120°C
• Exposure to aggressive chemicals or solvents
• FDA-compliant or medical applications requiring repeated steam or autoclave sterilization
• Metal replacement where weight reduction is critical (PEEK is ~80% lighter than steel)
• Radiation environments (PEEK has excellent gamma and X-ray resistance)
• Applications requiring both high strength and chemical inertness simultaneously

Visit our PEEK material page for available stock forms and grades.

When to Choose POM

POM is the smarter choice for the majority of precision mechanical applications:

• Gears, bearings, bushings, and sliding elements where low friction is key
• Food processing equipment operating at moderate temperatures (POM is FDA-approved for food contact)
• Precision components requiring tight tolerances and excellent surface finish
• Cost-sensitive applications and higher production volumes
• General mechanical parts replacing metal in ambient-temperature environments
• Valve and pump components in non-acidic media

If you’re also considering nylon as an alternative to POM, our POM vs PA comparison covers that decision in detail. For stock forms and specifications, see our POM material page.

Conclusion

Don’t default to PEEK when POM will do the job. POM covers roughly 80% of precision mechanical applications at a fraction of the cost. It machines beautifully, has excellent dimensional stability, and offers natural lubricity that PEEK can’t match without fillers.

PEEK earns its place when the application genuinely demands it — high temperatures, aggressive chemicals, sterilization cycles, or structural loads that exceed what POM can handle. In those cases, PEEK’s premium price is justified by performance that no other thermoplastic can deliver.

The best approach is to start with POM and move to PEEK only when the application requirements rule POM out. If you’re unsure, we’re happy to help you evaluate both options.