Dupont Delrin rod and Acetal Rods

Many of our clients assume that Delrin rod and Acetal rod is the same thing. This is not quite true. Yes, all Delrin rod is Acetal rod, but not all Acetal rod is Delrin rod. Delrin is a trade name for Homo-Polymer Acetal made by Dupont. This is the most recognized of all Acetal materials, but far from the only available Acetal material.Black and Natural Acetal - Delrin Rod
The Co-Polymer Acetal is produced by a wide variety of large plastic manufacturers, BASF is probably one of the largest and most well known. Some main resin names are: BASF Ultraform H4320, Kepital F10-02, or Hostaform M25. While Delrin is a wonderful material, in larger cross sections or larger diameters, the Delrin brand Homo-Polymer can exhibit center line porosity. This can sometimes be seen with the naked eye, and is a darker white in a normally milky white natural colored material. This center line porosity can cause problems in some applications. This porosity can cause leakage of fluid if under pressure, or ‘soft centers’ of Delrin Rod and Delrin Sheet.

This should not stop you from considering Delrin though. Many other properties of the Delrin resin are superior to the Co-Polymer resins. These properties are:

General Property ASTM
Test
Typical Value
Unfilled Delrin®

Homo-Polymer
Typical Value
Unfilled Co-Polymer
Specific Gravity D792 1.42 1.40
Tensile Strength Yield D638 9,600 – 11,000 9,000 – 10,200
Tensile Modulus D638 450,000 400,000
Izod Impact – Notched D256 1.2 1.0
Hardness – Rockwell D785 M94 M90
Deflection Temp @ 264psi D648 257 220
Deflection Temp @ 66 psi D648 347 335
Water Absorption @ 24 hrs
% 0.24 0.25
Co. Thermal Expansion D696 6.83X10-5 5.4X10-5

The key properties that Delrin are: higher tensile strength, increased Izod impact, higher deflection temperatures and it is slightly harder. The co-efficient of thermal expansion is a bit higher, and needs to be considered when designing a new part. Delrin brand material also comes in several resin variations, including: Delrin 150 and Delrin 507, contact us for details.

Many of our clients prefer the Delrin brand rod and sheet for small machined parts. This is due to the increase in a few key properties, and of course brand recognition. Both resins meet the standard ASTM-D-6778, and the cancelled specs, L-P-395 and ASTM-D-4181.Colored Acetal - Delrin Rod - Pomalux

The Acetal family of plastic resins are excellent for wear resistance, great mechanical strength, and superior machining properties. It is available in a huge range of sizes and shapes. Click here for more details on Acetal – Delrin Rod, and sometimes referred to as plastic dowel. We also have the capacity to supply colored Acetal – Delrin rod; click here from more details on the colored Acetal material.

Similar materials to Acetal – Delrin are Nylon Rod, PET Rod and Noryl Rod. Most materials are available as round rod, square rod, bar, strip, sheet and plate.

Please contact us for more details on these and other plastic materials. For a comparison chart of plastic materials click here: Plastic Materials Selection Guide

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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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