POM is a precision material. It machines like brass, moulds to tight tolerance, holds its dimensions in humidity, and has a natural lubricity that makes it the default for gears, latches and valve internals. It is also the least forgiving thermoplastic we run — hold the melt too hot and it releases formaldehyde, so process discipline is not negotiable.
Typical values for standard moulding grades. Exact figures depend on the specific compound or grade — confirm against your drawing before quoting.
Key properties
| プロパティ | Typical value |
|---|---|
| 密度 | 1.41 – 1.42 g/cm³ |
| Tensile strength | 60 – 70 MPa |
| Flexural modulus | 2.5 – 2.9 GPa |
| HDT at 1.8 MPa | 90 – 110 °C |
| Mould shrinkage | 1.8 – 2.2 % |
| Water absorption (24 h) | 0.2 – 0.3 % |
Values are typical for unfilled moulding grades at 23 °C unless stated. Glass-filled and specialty grades differ.
Typical applications
- Precision gears and worm wheels
- Snap-fit latches and clips
- Valve bodies, stems and pump internals
- Conveyor chain links and rollers
- Automotive window and seat mechanisms
Processing notes
- Melt 190 – 210 °C and never above 230 °C. Overheating decomposes POM into formaldehyde, which corrodes the tool and endangers the operator.
- Mould 80 – 100 °C. A hot mould is essential for dimensional stability and to avoid the voids that appear in thick sections.
- POM has a sharp melting point and poor melt strength. Design generous gates and avoid long thin flow paths.
- Shrinkage of about 2 % is high and anisotropic. For gears, cut the tool to the mean and adjust the tooth profile after T1 rather than guessing at design stage.
Frequently asked questions
Can POM be used in contact with fuel or chlorine?
POM resists fuels and many solvents well, but it is attacked by strong acids, chlorine and hot alkalis. Tell us the exact media and temperature — for chlorine service we would normally steer you to PP or PVDF.
Why did my acetal parts come out with a strong smell and a corroded tool?
That is thermal decomposition from an over-hot melt or a long residence time. It is a process fault, not a material fault, and it permanently damages the tool surface. We set residence-time limits on the machine and purge at shutdown.
Related materials
← All Injection Molding Solutions
Send us your POM drawing
Upload a 3D model or a 2D drawing and we will come back with a DFM review, a tooling cost and a piece price — usually within two working days.
JA 
EN 
ES 
FR 
DE 
PT 
AR 
RU 
KO 
IT 
NL 
TR 
PL 
ID 