POM (acetal / Delrin)
Density of POM (acetal / Delrin)
1,410 kg/m³ (1,400–1,420)
1.41 g/cm³ · 88.0 lb/ft³
The plastic engineers reach for when a part must be machined to size and stay there: unlike nylon it barely absorbs water, so a POM gear cut in a dry workshop still fits in a damp one. It is stiff, slippery and fatigue-resistant, which is why plastic gear trains default to it. Two catches: it cannot be glued reliably by any common adhesive, and it depolymerizes if overheated, releasing formaldehyde — machine it cool and never leave it sitting in a hot barrel.
Properties
- Density
- 1,410 kg/m³ (1,400–1,420) — 1.41 g/cm³
- Melting range
- 165–175 °C
- Tensile strength
- 60–75 MPa
- Young's modulus
- 3 GPa
- Thermal conductivity
- 0.31 W/(m·K)
- Thermal expansion
- 110 µm/(m·K)
- Floats in water
- No
- Magnetic
- No
What it is used for
- Gears, cams and bushings
- Zip fastener sliders and buckles
- Fuel system and pump components
- Machined precision parts
How it compares
Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.
air 1.2 kg/m³
expanded polystyrene foam 20 kg/m³
rigid polyurethane foam 40 kg/m³
Water — the float line 1,000 kg/m³
POM (acetal / Delrin) 1,410 kg/m³
tungsten 19,250 kg/m³
gold 19,300 kg/m³
platinum 21,450 kg/m³
| Material | Density | Relative to water |
|---|---|---|
| rigid polyurethane foam | 40 kg/m³ | 0.04× |
| expanded polystyrene foam | 20 kg/m³ | 0.02× |
| air | 1.2 kg/m³ | 0.00× |
| POM (acetal / Delrin) ← | 1,410 kg/m³ | 1.41× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |
Does it rust?
POM (acetal / Delrin) contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.
Is it magnetic?
POM (acetal / Delrin) is not a metal and has no ferromagnetic response.
Common questions
- What is the density of POM (acetal / Delrin)?
- 1,410 kg/m³ (1,400–1,420), or 1.41 g/cm³.
- Does POM (acetal / Delrin) float?
- No. At 1,410 kg/m³ it is denser than water.
- Is POM (acetal / Delrin) magnetic?
- POM (acetal / Delrin) is not a metal and has no ferromagnetic response.
Related pages
- Does POM (acetal / Delrin) float? No
- PLA 1,240 kg/m³
- ABS 1,050 kg/m³
- Acrylic (PMMA) 1,180 kg/m³
- Polycarbonate 1,200 kg/m³
- Polypropylene 905 kg/m³
- PTFE 2,170 kg/m³
- Rigid PVC 1,400 kg/m³
- HDPE 955 kg/m³
Sources
- Typical range compiled from manufacturer specifications — At One Place