How to Select the Right Elastomer for Sealing Boots and Fasteners

Word from APM Hexseal…

Elastomers for sealing boots and fasteners

More than 20 different types of standard elastomers exist, and each possesses unique functions in both process equipment and finished products.

How-to-Select-the-Right-ElastomerElastomers are the key to providing effective sealing solutions for applications in outdoor, marine, medical and any environment where sealing stuff in or sealing stuff out is imperative. Elastomers are versatile materials typically composed of polymers, and manufacturers prize them for their ability to bend and stretch in a variety of ways before returning to their original shape.

However, not all elastomers are the same. Elastomers can incorporate a wide range of designs and materials depending on the needs of their intended application. More than 20 different types of standard elastomers exist, and each possesses unique functions in both process equipment and finished products.

Different elastomer formulations affect the physical properties, functions, and service life of your components and systems. This is why it’s essential to test a few different elastomers to determine the best one for your needs. In this post, we outline ways to evaluate elastomers for their capacity to perform well in your application, and we also describe some of the best uses of each different type of elastomer.


Where and how will the sealing boots or fasteners be used? Applications that use elastomers can appear in many different environments, such as:When you’re trying to determine the best kind of elastomer to use for your sealing or fastening application, keep the following few questions in mind:

    • Outdoor
    • Marine
    • Industrial/manufacturing environments
    • Drilling and downhole
    • Food and beverage (some elastomers have FDA approval; others don’t)
    • Aerospace
    • Construction
    • Medical
  • What kind of contaminants will the sealing boots or fasteners come into contact with?
    • Different elastomers hold up better against specific environmental conditions or contaminants.
  • Will the sealing boots or fasteners experience extreme temperatures or wide temperature fluctuations?
  • Will the elastomer be exposed to sharp objects or coarse surfaces or need to withstand a high number of actuations or repeated human contact?
  • What is your budget compared with the cost of failure?


Compression molding is another area that benefits from the use of elastomers. The compression molding process takes high-viscosity compounds and processes them into a pre-form. It then compresses the pre-form into a mold before curing it.Even though many differences exist between the types of elastomers on the market, they all bring unique advantages to injection molding processes and products. The injection molding process forces rubber compounds into a mold using high pressure. Elastomers perform well in this type of environment because they’re made of similar materials as those used in injection molding.

Elastomers work well in a variety of hostile environments, such as:

  • Extreme temperatures
  • Corrosive oils and chemicals
  • Food and beverage applications
  • Road salt distribution
  • Dirt, dust, and sand
  • Water
  • Extreme weather


Building quality sealing boots or fasteners involves accounting for many variables. Fortunately, we at APM Hexseal bring years of experience to the elastomer design process, helping customers across the globe find ways to get the most from their elastomer options.

We’ve compiled our extensive experience from working with elastomers into our eBook, “Elastomer Shlastomer, Right?”, which is available for download here. If you would like to learn more about our full selection of products and services, contact us today and Ask the Experts at APM Hexseal.



We are honored to serve as a manufacturer’s rep for APM Hexseal. APM Hexseal has an extensive line of standard silicone sealing boots that mate with the vast majority of switches, breakers, encoders, potentiometers and many other rotating devices found today throughout the world.