POM-H (Acetal Homopolymer) vs POM-C (Acetal Copolymer): Same POM family — H is slightly stronger, C is more stable
POM-H (Acetal Homopolymer) vs POM-C (Acetal Copolymer)
Side-by-side chemical composition and mechanical property comparison.
Overview
POM-H (Acetal Homopolymer)
Polyoxymethylene Homopolymer — slightly stronger and stiffer than POM-C copolymer but with centerline porosity in stock shapes and lower resistance to hot water/alkalis. Trade names include Delrin (DuPont/DuPont de Nemours) and Tenac (Asahi Kasei). Used for gears, cams, springs, clips, fuel system components, and precision-machined parts where maximum stiffness is needed.
POM-C (Acetal Copolymer)
Polyoxymethylene Copolymer — the precision engineering plastic. Exceptional dimensional stability, low moisture absorption (0.2%), low friction coefficient, and excellent machinability. More hydrolysis-resistant and chemically stable than POM-H (homopolymer). No centerline porosity in stock shapes. Trade names include Hostaform (Celanese), Ertacetal C (MCAM), Duracon (Polyplastics). Used for gears, bearings, valve bodies, pump parts, electrical insulators, and food/medical contact parts.
| POM-H (Acetal Homopolymer) | POM-C (Acetal Copolymer) | |
|---|---|---|
| Material Number | — | — |
| Category | Polymers | Polymers |
| Standard | ISO 10350 | ISO 10350 |
Chemical composition (wt%) — Pro
| Element | POM-H (Acetal Homopolymer) | POM-C (Acetal Copolymer) | Overlap |
|---|---|---|---|
| Polyoxymethylene (OCH2 homopolymer) | 99–99.9% | — | — |
| Polyoxymethylene (OCH2 units) | — | 95–99% | — |
| Ethylene Oxide Co-Monomer | — | 1–5% | — |
Mechanical properties — Pro
| Property | POM-H (Acetal Homopolymer) | POM-C (Acetal Copolymer) | Unit |
|---|---|---|---|
| Tensile Strength | 66–73 | 60–67 | MPa |
| Yield Strength | 65–70 | 58–62 | MPa |
| Elongation | 15–25 | 25–45 | % |
| Elastic Modulus | |||
| Density | |||
| Melting Point | |||
| Water Absorption (24h) | |||
| Continuous Use Temp |
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POM-H (Delrin) has ~10% higher UTS (70 vs 64 MPa) and stiffness but has centerline porosity in stock shapes and is less resistant to hot water and alkalis. POM-C has no porosity, better hydrolysis resistance, and more consistent properties. Choose POM-H for max stiffness (springs, clips); POM-C for general machined parts and chemical exposure.
Frequently Asked Questions
Is POM-H (Acetal Homopolymer) the same as POM-C (Acetal Copolymer)?
POM-H (Acetal Homopolymer) and POM-C (Acetal Copolymer) have a 85% composition overlap. Same POM family — H is slightly stronger, C is more stable
Can I replace POM-H (Acetal Homopolymer) with POM-C (Acetal Copolymer)?
In many cases, yes. The compositions overlap significantly (85%). However, always verify mechanical property requirements and heat treatment compatibility for your specific application.
What is the difference between POM-H (Acetal Homopolymer) and POM-C (Acetal Copolymer)?
The main differences are in the following elements: overall alloying content. POM-H (Acetal Homopolymer) is a Polymers grade, while POM-C (Acetal Copolymer) is a Polymers grade.
Related Comparisons
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Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.