FKM vs NBR O-Rings

FKM vs NBR O-Rings

FKM and NBR are two of the most commonly used O-ring materials in industrial sealing applications. Understanding the differences between FKM vs NBR O-rings helps engineers and buyers select the most suitable material for their operating conditions.

Overview of FKM and NBR O-Rings

Both FKM (fluoroelastomer) and NBR (nitrile rubber) offer excellent sealing performance, but they differ significantly in temperature resistance, chemical compatibility, and cost.

FKM vs NBR O-Rings Comparison Chart

Property FKM (Viton®) O-Rings NBR (Buna-N) O-Rings
Temperature Range -20°C to +200°C -40°C to +120°C
Oil & Fuel Resistance Excellent Very Good
Chemical Resistance Excellent (acids, solvents) Moderate
Compression Set Low Moderate
Cost Higher Lower

Advantages of FKM O-Rings

  • Superior heat resistance
  • Excellent chemical compatibility
  • Long service life in harsh environments
  • Ideal for oil, fuel, and solvent exposure

View FKM (Viton®) O-Rings

Advantages of NBR O-Rings

  • Cost-effective sealing solution
  • Excellent oil and fuel resistance
  • Good mechanical strength
  • Wide availability of standard sizes

View NBR (Buna-N) O-Rings

Which Should You Choose: FKM or NBR?

The choice between FKM and NBR O-rings depends on your application requirements:

  • Choose FKM for high temperature or aggressive chemical environments
  • Choose NBR for general oil sealing at lower cost
  • Consider pressure, temperature, and fluid compatibility

Hardness and Size Availability

Both FKM and NBR O-rings are available in multiple hardness grades and standard sizes.

  • Hardness range: 60 – 90 Shore A
  • Available in AS568 and metric sizes

Refer to our O-Ring Hardness Chart and Standard O-Ring Size Overview for detailed guidance.

Custom O-Rings & OEM Manufacturing

We provide both FKM and NBR O-rings in standard and custom dimensions, hardness, and colors. OEM and bulk orders are supported with strict quality control.