Materials
PEEK vs POM for Machined Equipment Components
PEEK and POM are both machinable engineering plastics, and equipment builders pick between them constantly. They are not interchangeable. PEEK wins where temperature, creep and chemical resistance decide the design. POM wins where friction, stiffness at room temperature and cost decide it. This page is the short version of that decision.
Side-by-side
Comparison
| Property | PEEK | POM (acetal / Delrin) |
|---|---|---|
| Max. service temperature | 260 °C | about 100 °C |
| Friction | Low | Very low |
| Stiffness at room temperature | High | High |
| Moisture absorption | Very low | Moderate |
| Chemical resistance | Broad | Good, but attacked by strong acids and alkalis |
| Wear in sliding contact | Good with a bearing grade | Excellent |
| Machining behaviour | Sharp tooling, stable once stress-relieved | Sharp tooling, prone to smearing |
| Relative cost | Higher | Lower |
| Typical equipment use | Semiconductor, medical and analytical housings | Gears, bushings, sliding guides and wear parts |
Decision guide
How to decide
- Choose <strong>PEEK</strong> for structural parts in equipment that runs warm, sees chemicals, or has to hold its dimensions over time — semiconductor wafer handling, medical instrument housings, analytical manifolds.
- Choose <strong>POM</strong> where the part is a wear component at normal temperature — gears, bushings, sliding guides, fixtures — and where cost matters more than temperature capability.
- Choose <strong>filled PEEK (CF30, GF30, HPV)</strong> when stiffness or creep resistance matters more than the price of the unfilled grade.
- Choose <strong>unfilled PEEK</strong> when the part has to be optically inspected, or when the drawing specifies a medical grade.
- Do not choose <strong>POM</strong> for parts that run above about 100 °C, or that see strong acids or alkalis.
- Still unsure? Send the drawing and the duty — temperature, load and environment. We will tell you which one we would machine and why.
FAQ
Frequently asked questions
There is no single winner. PEEK wins on service temperature, creep behaviour and chemical resistance; POM wins on friction, stiffness at room temperature and cost. For structural parts in equipment that runs warm, use PEEK. For gears, bushings and wear parts at normal temperature, use POM.
Both need sharp, positive-geometry tooling and controlled feeds; neither likes a dull tool. PEEK is dimensionally stable once stress-relieved, so the part stays predictable. POM is more prone to smearing and needs tighter chip control, and it creeps more under sustained load.
±0.01 mm on both — plastics are held to ±0.01 mm, not the ±0.005 mm we hold on metals. PEEK benefits from a stress-relaxation step before final measurement. POM creeps more, so for the tightest dimensions we confirm the grade and the finish with you rather than promising a number we cannot hold.
Yes. PEEK in unfilled, CF30, GF30 and HPV grades, and POM, are both machined in our own plant, so a machine builder can consolidate two part families into one supplier and one inspection routine.
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