Semi-Crystalline Engineering Thermoplastic

Acetal (POM) Homopolymer and Copolymer

Acetal, or polyoxymethylene (POM), is a stiff, low-friction engineering plastic with excellent dimensional stability. Delrin is DuPont’s homopolymer brand name; copolymer grades offer better resistance to porosity and hot water. Request a quote or browse all materials.

Typical Properties

Delrin / POM (Acetal) at a glance

Property	Typical value
Density	~1.41–1.42 g/cm³
Tensile strength	~60–75 MPa
Tensile/flexural modulus	~2.6–3.1 GPa
Elongation at break	~25–40%
Hardness	~M80–M94 Rockwell
Heat deflection (1.8 MPa)	~95–125 °C
Melting point	~165 °C (copolymer) / ~175 °C (homopolymer)
Water absorption (24 h)	~0.2–0.25%

Ranges cover common homopolymer and copolymer stock grades. These are typical reference values from standard published data, not guaranteed minimums. Request material certificates in your RFQ if properties must be verified.

Advantages

Why engineers choose Delrin / POM (Acetal)

Machinability

Machines cleanly to tight tolerances with a good finish.

Low friction

Self-lubricating behavior for gears, bushings, and slides.

Stability

Low moisture absorption keeps dimensions stable.

Fatigue

Good fatigue and creep resistance for snap fits and springs.

Design considerations: Difficult to bond and paint; poor resistance to strong acids and UV; homopolymer can show centerline porosity in thick stock.

Applications