Delrin (Acetal / POM) properties
Delrin is the trade name for acetal homopolymer (POM), an engineering thermoplastic prized for its stiffness, low friction, dimensional stability, and machinability. It is a favorite for precision machined plastic parts.
Mechanical properties
| Property | Value |
|---|---|
| Tensile strength | 10,000 psi (69 MPa) |
| Flexural modulus | 450,000 psi (3.1 GPa) |
| Elongation at break | 25% |
| Hardness | Rockwell M94 / Shore D 86 |
Physical properties
| Property | Value |
|---|---|
| Density | 0.051 lb/in³ (1410 kg/m³) |
| Melting point | about 175 °C |
Thermal properties
| Property | Value |
|---|---|
| Max service temperature | about 90 °C continuous |
| Thermal expansion | 110 µm/m·°C |
| Thermal conductivity | 0.31 W/m·K |
Values are typical for the grade and condition shown. Actual properties vary with temper, heat treatment, and product form, so use these for comparison and preliminary design and confirm against material certificates for final work.
Compare with other materials
See the Material Properties Comparison, Yield Strength, and Density charts.
Typical uses
Delrin is used for gears, bushings, bearings, rollers, fasteners, and precision mechanical parts. Its low friction, stiffness, and dimensional stability let it replace metal in many moving parts, and it machines cleanly to tight tolerances.
How it compares
Delrin is stiffer and more dimensionally stable than nylon and absorbs far less moisture, so its size and properties hold steady. It is stronger and more rigid than UHMW or HDPE, making it the choice for precise machined components rather than wear liners.
FAQ
What is Delrin used for?
Precision machined parts: gears, bushings, bearings, rollers, and fasteners, where stiffness, low friction, and dimensional stability matter.
Is Delrin the same as acetal?
Delrin is a brand of acetal homopolymer (POM). Acetal copolymer is a related grade with slightly different properties but similar uses.
Does Delrin absorb water?
Very little, far less than nylon, which is why it holds its dimensions and properties so well in humid or wet conditions.