What O-Ring Material Do I Need?

O-Ring Materials For Every Application

O-rings and seals are used in a wide range of industries to help keep important application medium in the system and damaging elements out. O-rings are one of the most common seals used in critical applications because they are inexpensive and reliable, and have simple mounting requirements.

However; one-size does not fit all and no two materials are created equal.

Because of the wide-variety of industries, applications, and critical requirements, there is a large library of materials and specialty compounds. Proper selection is crucial to the success of your application.

For over 50 years, ESP has been the leading engineering choice for both standard and custom sealing applications. Let our in-house seal engineering experts help in your selection.

Not sure the best solution?

Ask One Of Our O-Ring Experts!

O-Ring Material Selection Quick Reference Cheat Sheet

Material ASTM Shelf Life (Years) Hardness (Shore A) Low Temp (F°) High Temp (F°) Recommended For
Nitrile (Buna) NBR 15 40 - 90 -34 +212 Petroleum oils and fuels, silicone oils and greases, propane, ethylene glycol, butane, vegetable, mineral oils and greases, dilute acids, water and steam applications (below 212°F). General NBR Information
Hydrogenated Nitrile HNBR 15 50 - 90 -40 +300 Petroleum oils and fuels, R134a refrigerant gas, silicone oils and greases, ozone applications, improved compression set characteristics, vegetable and animal fats, fluids, water and steam (up to 300° F). General HNBR Information
Fluorocarbon (Viton®) FKM 25 55 - 90 -15 +400 Petroleum oils and fuel, mineral and vegetable oil and grease, silicone oils and greases, hard vacuum applications, solvents, water or steam (up to 400°F). General FKM Information
Perfluoroelastomer FFKM 25 65 - 90 -15 +572 Water and steam applications (below 212°F), petroleum oils and fuels, silicone oils and greases, propane, ethylene glycol, butane, vegetable, mineral oils and greases, and dilute acids. General FFKM Information
Ethylene Propylene EPDM 25 40 - 95 -70 +300 Hot water and steam with special compounds, gycol based and silicone-based brake fluids, ozone, aging and weather resistance, cleaning agents, silicone oil and grease, alcohols, ketones, esters. General EPDM Information
Silicone VMQ 25 20 - 80 -65 +400 For static applications Silicone o-rings offer high suitability in medical, food, pharmaceutical, semiconductor, automotive, aerospace, and electronics. Excellent in dry heat and ozone applications. General VMQ Information
Fluorosilicone FVMQ 25 40 - 80 -100 +350 FVMQ is widely used in aerospace, jet fuel applications, engine gaskets, automotive emission control systems, fuel pumps and tank systems. Not recommended for dynamic sealing. General FVMQ Information
Polyacrylate ACM 15 40 - 90 -5 +350 Optimal environments include engines and transmissions with good resistance to petroleum fuels and oils, automatic transmission fluid, type A power steering fluid. General ACM Information
Butyl Rubber (Isoprene) IIR 15 30 - 90 -75 +250 Recommended for general purpose applications, vacuum, and low compression set. General IIR Information
AFLAS® TFE/P 25 60 - 90 +15 +450 Phosphate esters, amines, steam and hot water, automotive engine coolants, motor oils, steering fluids and some brake fluids. General TFE/P Information
Polyurethane AU 5 40 - 90 -40 +180 Can be used with propane, butane, mineral oil and grease, silicone oil and grease. General AU Information

Additional Factors to Consider When Selecting O-rings (Besides Material)

Included but are not limited to:


Failure, improper selection or improper use of the products/materials and/or systems described herein or related items can cause death, personal injury or property damage. This information and other information from Engineered Seal Products provides product and/or system options for further investigation by users having technical expertise.

Due to the variety of operating conditions and applications for these products or systems, the user is solely responsible for making the final selection of the products and systems and assuring that all performance, safety and warning requirements of the application are met.

The products/materials described herein, including without limitation, product featuresand specifications are subject to change by Engineered Seals Products and its partner suppliers at any time without notice.