All You Need to Know About Acetal Plastic

When you are looking for the strength of a metal but the benefits of using plastic, consider acetal plastic. The thermoplastic was originally developed as an alternative to metal due to its tensile strength, low friction, and high-wear resistance. At Acme Plastics, we offer a variety of acetal plastic pieces in different shapes, sizes, and colors. Keep reading to learn more about the material, including its properties and uses.


What Is Acetal Plastic?

Acetal plastic, or Polyoxymethylene (POM), is a semi-crystalline, engineering thermoplastic that is resistant to moisture and many chemicals. There are 2 general types of acetal plastic:

  1. Copolymer acetal (POM-C) is free of centerline porosity which results in a lower coefficient of friction and better impact and wear properties in wet applications. It is food compatible and resistant to common cleaning agents used in the food industry.
  1. Homopolymer acetal (POM-H), or Delrin, which is a registered trademark of Dupont. Delrin offers greater stiffness, slightly better tensile and impact strength as well as a lower coefficient of friction. However, it is not used in the food industry. Delrin inherently has centerline porosity (internal voids in the material formed during the manufacturing process) which can allow liquid and gas leakages, as well as bacterial growth in certain conditions, making it not ideal for medical or food processing applications.

Properties of Acetal Plastic 

While the types of acetal plastic may be used for different applications, they share many mechanical properties, including:

  • high strength
  • hardness
  • rigidity
  • excellent resistance to most chemicals
  • stress-cracking resistance
  • excellent creep resistance and dimensional stability
  • low permeability and water absorption

These properties bring high stiffness, low friction, abrasion resistance, and excellent dimensional stability to a variety of applications. 

Benefits of Acetal Plastic

Acetal plastic is easy to machine, making it ideal for precision parts requiring high stiffness, low friction, and tight tolerances. The plastic can be free cut but only using tools with a sharp clearance angle. Sheets can be cut on a laser cutter.

It’s naturally opaque white, due to its high crystalline composition but it can be dyed in a variety of colors. Acme Plastic’s Rods and Sheets and available in natural and black colors. Also available, Acme Plastics’ Acetal ESD Natural rods and sheets have a ESD designation (electrostatic discharge materials), identifying plastics that reduce static electricity to protect sensitive electronics or contain flammable liquids.

What Are the Uses of Acetal Plastic?

 The benefits of acetal plastic—low friction, high stiffness, excellent dimensional stability—make it an excellent replacement material for metal. That said, it’s used frequently for mechanical parts such as gears, bearings, roller, wheels, sliding and guiding elements, housing parts, springs, chains, screws, nuts, fan wheels, pump parts, valve bodies, etc.

Other uses include:

  • Electrical engineering: insulators, bobbins, connectors
  • Consumer electronics: parts for electronic devices such as televisions and phones
  • Automotive parts: fuel sender unit, door lock systems, articulated shells
  • Musical instruments and accessories: bagpipes, Irish flutes, practice chanters, guitar picks and drumstick tips
  • Furniture: hardware, locks, handles, hinges, curtain roles
  • Medical supplies: insulin pens, metered dose inhalers
  • Food industry: milk pumps, automatic coffee brewers, knife handles
  • Fashion: zippers, eyeglass frames

What is Acetal ESD?

ESD stands for electrostatic dissipation. ESD can harm electronics components and magnetic media as well as cause sparks. Acetal ESD plastics are designed to reduce static electricity to protect sensitive electronics or contain flammable liquids. Acetal plastic is not inherently an ESD plastic. If you require an ESD plastic, you need to look for acetal plastics that have an ESD designation.

 Final Thoughts

Acme Plastics stocks acetal plastic in rods and sheets in any size, shape and color you need. Browse our full catalog or contact a representative today.