TIPS WITH TONY: New Silicone Rubber Materials

We’ve expanded our selection of liquid silicone rubber (LSR) materials, which have some distinct elastic and optical advantages over certain thermoplastics. In addition to three durometers of general-use Elastosil LSR, and medical- and optical-grade Dow Corning materials, we now have two new durometers of Elastosil and a fuel-resistant flourosilicone material at Proto Labs.

Elastosil LSR
Elastosil LSR is a great general-use material that has good moldability characteristics, a good overall appearance and is transparent until colorant is added. Shore A durometers of 40 and 60 have been added our current offering of 30, 50, and 70 durometers.

Technical specs:

  • 40 durometer Elastosil has a tensile strength of 10.0 N/mm² with a tear strength of 33 N/mm and an elongation break of 610%.
  • 60 durometer Elastosil has a tensile strength of 9.40 N/mm² with a tear strength of 27 N/mm and an elongation break of 340%.

Common uses:

  • Ignition technologies
  • Automotive, when fuels are not present
  • Seals and gaskets
  • Membranes
  • Food contact

Flourosilicone Rubber
We’ve also introduced a fuel- and oil-resistant fluorosilicone (Silastic FL 60-9201), which meets the standards required for some automotive applications. Like other LSR materials, flourosilicone also has high elasticity at low temperatures (-68°F) and high temperature resistance. Operating temperature ranges from -82°F to 347°F under immersive conditions and up to 437°F in dry heat.

Fluorosilicone is available in shore A durometer of 60, which has a tensile strength of 6.5 Mpa with a tear strength of 14 N/mm and an elongation break of 220%.

We’re always adding new plastic, metal and LSR materials, so stay tuned for updates throughout the year. If you have any questions on materials, feel free to contact us directly at 877.479.3680 or

This entry was posted in Tips with Tony and tagged , , , by Tony Holtz. Bookmark the permalink.

About Tony Holtz

Tony is a technical specialist at Proto Labs with more than 10 years of experience ranging from CNC mill operator to mold designer to customer service engineer. While his formal education is in industrial machinery operations, he has extensive knowledge and experience in both traditional and advanced manufacturing processes and materials. Throughout his tenure at Proto Labs, Tony has worked with countless designers, engineers and product developers to improve the manufacturability of their parts.

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