Acetal Plastic for CNC Machining

Versatile thermoplastic well-suited for machining projects.

POM-H acetal homopolymer material sample

What is Acetal? 

Acetal (polyoxymethylene or POM) is a strong, stiff, wear-resistant thermoplastic with excellent dimensional stability. It is also known by the trade name Delrin.

We offer four formulations of acetal plastics via our CNC machining service:

  • Acetal 20% Glass-filled/Delrin 570
  • POM (acetal copolymer) 
  • POM-H (acetal homopolymer)
  • POM (acetal static dissipative)

Key Benefits of Acetal

All forms of acetal have a lot going for them for machined parts. One of its most important features is its machinability. Endmills cut through it like butter, and those cuts tend to be clean and smooth. At the same time, precision parts can benefit from its high dimensional stability and tolerance for temperature and weight. Related to that is acetal’s strength and stiffness, which help it tolerate heavy loads. Acetal is also suitable for high-moisture environments as it is unlikely to swell in those conditions. Last but not least, that toughness means it’s also suitable for applications that experience friction. In some situations, it can even replace heavier metal parts, allowing for light-weighting.

Applications for Acetal Plastics

  • Bearings 
  • Bushings
  • Fasteners
  • Gears
  • High-moisture environments, such as washers, faucets, and more
  • Insulators for electrical components

Acetal Material Properties

  Ultimate Tensile Strength Impact Strength Heat Deflection More Information
Acetal 20% GF/Delrin 570 8.5 KSI
(58.6 MPa)
152 J/m 329° F
(165° C)
Data Sheet
(60.7 MPa)
53 J/m 316° F
(158° C)
Data Sheet
POM-H 11.1 KSI
(76.5 MPa)
80 J/m 329° F
(336° C)
Data Sheet
POM (static dissipative) 6.6 KSI 
(45.5 MPa)
101 J/m 190° F
(88° C)
Data Sheet

Additional Attributes of Acetal

  Acetal 20% GF/Delrin 570 POM (copolymer) POM-H (homopolymer) POM (static dissipative)
Antistatic       X
Chemical Resistance    X    
Creep Resistance     X  
Dimensional Stability    X    
FDA-approved   X
(in black)
(in natural)
Low Friction   X    
Moisture Resistance       X
Stiffness     X  
Strength X   X  
Temperature Resistance X      
Wear Resistance       X

The Acetal, POM, Delrin Plastics Family 

The four types of acetal we stock are all semi-crystalline thermoplastics. Delrin 570 differs from the others because it is 20% glass-filled to provide additional strength, stiffness, creep resistance, and dimensional stability. POM comes in two structural varieties, homopolymer and copolymer. The essential difference between these two is in the chemical structure, with the homopolymer using a chain of the same monomer (a carbon-based molecule), and the copolymer using multiple kinds of monomers to form the chain. The static dissipative version of POM is also a copolymer and a good choice for when you want to avoid issues with static discharge, such as near sensitive electronics where one zap from your finger can destroy a circuit board.