Product Spotlight

Silicone O-Rings: 4 Key Facts You Need to Know


Silicone o-rings are known for their retention of flexibility and low compression set characteristics within one of the widest working temperature ranges of all elastomers. These properties, among others, make silicone a key material for applications in medical, automotive, aerospace, electronics, and more.

From simple o-rings to complex parts, Apple Rubber offers a wide range of silicone sealing solutions and sophisticated processing capabilities to deliver a quality product every time. Find out if silicone o-rings are right for your application from our four key facts below.

1. Offers Excellent Resistance Properties

Silicone o-rings are widely sought after for their outstanding resistance properties to a wide range of chemicals, temperatures, and weather conditions. Specifically, silicone is known to feature:

  • Extreme temperature resistance from -155°F to 400°F
  • Superior insulating properties
  • Exceptional weather resistance to UV light, ozone, water, oxygen, moisture, and steam
  • Outstanding aging characteristics
  • Chemical resistance to oxidizing chemicals, some acids, ammonia, and isopropyl alcohol

2. Various Types and Forms of Silicone

Silicone can be formulated in various types—each providing different working properties that are key in specific environments. These types include:

  • Dimethyl Silicone: ASTM D1418 Designation VMQ. Used in general silicone applications
  • Phenyl Silicone: ASTM D1418 Designation PVMQ. Used in low temperature applications
  • Fluorosilicone: ASTM D1418 Designation FVMQ. Offers oil resistance properties
  • Liquid Silicone Rubber (LSR): ASTM D1418 Designation VMQ. Used in injection molding

In addition to multiple types of silicone, it also comes in many forms. High Consistency (HC) silicone is used in compression, transfer, and rubber injection, while LSR silicones are injection molded.

3. Can be Formulated to Meet Your Needs

Every silicone seal can be formulated to meet specific requirements, such as color, temperature ranges, insulation, and more. Depending on the application, silicone seals can be transformed for highly specific functions:

  • Silicone can insulate or be conductive
  • Withstand freezing temperatures and handle extreme heat
  • Can be almost any color, including translucent or glow-in-the-dark
  • Resists fungus and is non-toxic

Based on the excellent range of working properties, silicone is used in many applications in which organic rubber cannot perform.

4. Superior in Medical Applications

Silicone o-rings are available in FDA approved and medical compliant grades. Because of silicone’s non-toxic biocompatibility, it has become a key material for medical seals and devices. As medical technology continues to become smaller and more compact, microminiature silicone seals are becoming increasingly popular.

Silicone seals play an important role in the medical industry and are used in many life-saving applications, including:

  • Ventilators
  • Medical pumps
  • IV components
  • Feeding devices
  • Implant materials

Want to learn more about silicone o-rings?

Contact an engineer today.