Polyurethane (AU) O-Rings

Urethane (AU) O-Rings Material Description:

Urethane, polyurethane (AU) o-rings are produced by the poly addition reaction of a polyisocyanate with a polyol in the presence of a catalyst. AU has excellent wear resistance, high tensile strength, tear strength, extrusion resistance and elasticity in comparison with any other material. Can be used with propane, butane, mineral oil and grease, silicone oil and grease.

Engineered Seal Products has the expertise and inventory for your urethane (AU) o-ring applications. For over 50 years, ESP has been the leading engineering, quality, and supply chain choice for both standard and custom sealing applications. A seal, no matter the application, has to do just that.

Urethane (AU) Advantages:
  • Excellent wear resistance
  • High tensile strength
  • High tear strength
  • Extrusion resistance
  • Good elasticity
  • Excellent Ozone resistance
Urethane (AU) Disadvantages:

Incompatible for applications that come in contact with:

  • Alcohols
  • Ketones, esters and ethers
  • Glycols
  • Steam
  • Alkalis and Amines
  • Acids
  • Water resistant capable but only up to 125°F.

Urethane (AU) Material Properties

Urethane (AU) Material Temperature Range:

Heat Resistance: Up to approximately 180°F (82°C)

Cold Flexibility: Down to approximately -40°F (-40°C).

Normal Recommended Temperature Range Normal recommended temperature range

Extended Temperature Range Extended Temperature Range for short term only

PDF O-Ring Temperature Range Chart

Abrasion Resistance Excellent
Chemical Resistance Fair/Good
Cold Resistance Good
Heat Resistance Fair
Oil Resistance Good
Ozone Resistance Excellent
Tensile Strength Excellent
Water/Steam Resistance Poor

Material properties & Temp ranges based on Parker o-Ring Handbook (ORD 5700) recommendations.

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ASTM Designation
Shelf Life
5 Years
Hardness (Shore A) Range
40 - 90

Temperature ranges will apply to the majority of media for which the material is potentially recommended. With some media however, the service temperature range may be significantly different. ALWAYS TEST UNDER ACUTAL SERVICE CONDITIONS.

ESP’s shelf life recommendation is based on the ARP 5316 standard and intended to be utilized by those organizations who do not already have specific recommendations for the control of elastomeric seals. It should be noted that the packaging of the elastomeric seals prior to assembly into a product is an integral part of the controlled storage procedure. It provides a positive means of product identity from the time of manufacture, to the time of assembly.