Acetal Versus Delrin


Is Delrin® the same as Acetal?

This is one of our most common questions, and is a bit difficult to answer.

All Delrin® is Acetal (PolyOxyMethylene or POM).

Acetal is the generic, and not all Acetal is Delrin®. Several manufacturers produce Acetal resin, including: Celanese®, BASF®, Ticona®, SABIC® and many more.

Copolymer versus Homopolymer AcetalAcetal vs Delrin®

Delrin® is a homo-polymer Acetal produced by Dupont. The generic Acetal covers both the homo-polymer Delrin® and the co-polymer grades of resin. Both materials meet the ASTM-D-4181, ASTM-D-6100 or ASTM-D-6778 specification (an old call out is L-P-392). Homo-polymer is POM111, and Co-polymer is POM211.

Both are tough and machinable, and have very similar properties.

An additional difference is the inherit problem of center-line porosity in the homo-polymer grades. This is caused by out gassing during manufacturing, and can be found at the center or on the surface of all homo-polymer extrusions. This porosity can cause problems with machining or moisture permeation through the material. The co-polymer resin does not have this porosity issue.

Some of the other differences are in the physical properties of the resin. Review the chart for some of the most popular properties people ask for when looking at Acetal or Delrin.

See Delrin® / Acetal properties chart below.

Properties Homo-Polymer Acetal Co-Polymer Acetal
Tensile Modulus of Elasticity 450,000 400,000
Flexural Modulus of Elasticity 470,000 366,000
Heat Deflection Temp @ 264 psi – degress F 257 220
Melting Point – degress F 347 335
Coef. of Linear Thermal Expansion 6.8 x 10-5 5.4 x 10-5
Water Absorption @ Saturation 0.90 0.80

Material is available as Delrin® Rod, Acetal Rod, Delrin® Block, Acetal Block, Delrin® Sheet, Acetal Sheet, and Slabs. Acetal is one of the most widely available plastics, especially on the West Coast (for some reason the East Coast like the Nylon – Polyamide material more). Most commonly available in Natural (White) or Black, but can be produced in a wide range of colors with minimum orders. This enables material matching your product color or for easy identification of parts.

While these properties are similar, depending on your application, one material may be better suited than the other. Review our Delrin® / Acetal page for additional information on the product availability and data sheets. We get calls for Delrin® product, only people may call it Delron, Delran, Delrun, Derlin and many other names, but it is still Delrin® to us.

Looking for other colors of Acetal – Delrin® Rod?

Contact us today for more information on Acetal – Delrin® or any other plastic material.

Call us at 866-832-9315 or Email Us for more additional details

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