One must differentiate between polyester urethane (AU) and polyether urethane (EU). AU type urethanes exhibit better resistance to hydraulic fluids. Polyurethane elastomers, as a class, have excellent wear resistance, high tensile strength and high elasticity in comparison with any other elastomers. Permeability is good and comparable with butyl rubber.

Both o-rings and gaskets can be made from EPDM materials.

Names: PolyurethaneMillable PolyurethaneAUEU

Compound Info

ASTM D1418 DesignationAU, EU
ASTM D2000/SAE J200 Type, ClassBG
Hardness (Shore A)40-90

Thermal Properties

Standard Min Temp.-30°F (-34°C)
Max Temp.175°F (79°C)

Chemical Resistance

Pure aliphatic hydrocarbons (propane, butane, fuel)
Mineral oil and grease
Silicone oil and grease
Water up to 125°F(50°C) (EU type)
Ozone and aging resistance

NOT Compatible

Ketones, esters, ethers, alcohols, glycols
Hot water, steam, alkalis, amines, acids

Disclaimer: These are general guidelines only. All materials should be tested in your application.