Key Properties of POM (Acetal) for CNC Plastic Machining
2025.12.01
POM (Polyoxymethylene), commonly referred to as acetal or polyacetal, is a highly popular engineering plastic among mechanical design engineers due to its excellent dimensional stability and rigidity. It maintains its shape under load, resists deformation, and delivers strong mechanical performance.
With its high melting point and low friction characteristics, POM is also widely used as a CNC plastic machining material, especially for small gears, wheels, bearings, caps, eyewear frames, and various precision mechanical components that require strength and wear resistance.
How POM Is Produced
More than 500,000 tons of POM are produced annually.
Its primary raw material is formaldehyde. A common method involves producing trioxane—a cyclic trimer of formaldehyde—and polymerizing it with ethylene oxide to create POM resin.
Advantages of Using POM for CNC Machining
Impact Resistance
POM withstands sudden mechanical impact and does not easily crack or break. This makes it highly suitable for precision CNC-machined plastic parts that require durability.
Excellent Wear Resistance
With high crystallinity and a naturally low coefficient of friction, POM offers outstanding wear performance.
It is ideal for CNC-machined gears, cams, sliders, and other components involving repeated motion.
Heat Resistance
POM can tolerate short-term exposure to temperatures around 302°F(150°C), and its heat deflection temperature (1.8 MPa) is approximately 230°F - 248°F(110–120°C).
This makes it suitable for CNC-machined components used near engines, heaters, and other high-temperature environments.
Dimensional Stability
POM maintains its shape and dimensional accuracy even when exposed to heat or humidity.
Its minimal deformation makes it one of the most preferred plastics for tight-tolerance CNC machining.
Chemical Resistance
Aside from strong acids, POM provides excellent resistance to fuels, lubricants, and most chemicals—making it a reliable choice for CNC-machined parts used in fluid-handling or lubrication environments.
Considerations When Using POM
Low Transparency
Due to variations in molecular alignment, POM refracts light irregularly and appears opaque.
Weak UV Resistance
Long-term outdoor exposure or direct sunlight can degrade the material.
Poor Adhesion
POM does not bond well with standard adhesives. For CNC-machined assemblies, mechanical fastening (screws, clips, snap-fits) is recommended instead of bonding.
Flammability
POM contains oxygen atoms in its structure, giving it a relatively high oxidation index and making it more susceptible to burning.
Start CNC Machining POM with Creallo
Upload your 3D model with POM specified as the desired material to Creallo’s AI-powered instant quoting system.
You’ll receive real-time feedback on machinability, pricing, and estimated lead time.
With fast checkout and secure delivery, Creallo enables quick and reliable production of CNC-machined POM components.
Need CNC-machined POM parts?
Check manufacturability and cost in under 1 minute with Creallo’s AI-based instant quote.
