Specification Grade Silicones

AMS3357 Silicone

AMS3357 silicone meets and AMS standard for a silicone rubber (VMQ) elastomer designed to be resistant to aircraft piston engine lubricating oils and have good compression set resistance, with a hardness range of 65-75 Durometer Type A. This aerospace-grade specification applies to silicone material used for various products including solid sheets, strips, tubing, extrusions, and molded shapes, and requires compliance with demanding industry standards for performance and reliability.

This aerospace fluorosilicone and military fluorosilicone is Made in USA under an AS9100D and ISO 9001:2015 quality management system (QMS). ElastaPro provides a full Certificate of Analysis (COA) with every batch for traceability.

AMS3357 Silicone Properties

Key Characteristics of AMS3357 silicone:

  • Material: Silicone Rubber (VMQ)
  • Resistance: Resists aircraft piston engine lubricating oils
  • Hardness: 65-75 Durometer Type A
  • Specification: Covers a range of products including sheets, strips, tubing, extrusions, and molded forms.

FAQs for AMS3357 Silicone

What is AMS 3357 silicone?

AMS 3357 is a high‑temperature, high‑strength silicone rubber defined by SAE’s Aerospace Material Specification. It typically covers 70‑durometer solid silicone engineered for demanding aerospace environments requiring thermal stability, mechanical durability, and long‑term compression‑set resistance.

What temperature range does AMS 3357 typically support?

AMS 3357 silicones generally operate from –65°F to +500°F (–54°C to +260°C), making them suitable for engine‑bay components, high‑heat enclosures, and thermal‑cycling environments common in aerospace platforms.

What applications commonly specify AMS 3357 silicone?

Engineers use AMS 3357 for:

  • High‑temperature gaskets and seals
  • Engine‑bay insulation interfaces
  • Aerospace ducting seals
  • Thermal shields and vibration‑isolating components
  • High‑compression sealing profiles where mechanical strength matters

How does AMS 3357 differ from AMS 330X silicones?

Compared to the AMS 3301–3304 family, AMS 3357 offers:

  • Higher durometer (typically 70A)
  • Greater tensile strength and tear resistance
  • Higher upper‑temperature capability
  • Better performance in high‑load, high‑compression sealing environments

It is not a general‑purpose silicone; it is chosen for thermal and mechanical durability.

Is AMS 3357 fuel‑ or solvent‑resistant?

No. Like most standard silicones, AMS 3357 is not compatible with fuels, oils, or aggressive solvents. For exposure to jet fuel, hydraulic fluids, or aromatic hydrocarbons, engineers should specify fluorosilicone (e.g., AMS 3325, AMS 3326, AMS 3327, or AMS 3305J‑type materials).

What hardness is AMS 3357 typically supplied in?

AMS 3357 is generally produced in 70 Shore A hardness. This durometer supports higher mechanical loads, better dimensional stability, and improved resistance to extrusion under pressure.

Does AMS 3357 offer good compression‑set resistance?

Yes. AMS 3357 is engineered for low compression set, even after long‑term exposure to elevated temperatures. This makes it suitable for static seals that must maintain sealing force over thousands of hours.

Is AMS 3357 suitable for aerospace electrical or avionics enclosures?

It can be, depending on the thermal environment. AMS 3357 provides excellent heat resistance, but if the enclosure requires EMI shielding, fuel resistance, or low‑outgassing, a different silicone or fluorosilicone formulation may be more appropriate.

What certifications or quality systems are typically associated with AMS 3357 materials?

Aerospace suppliers commonly produce AMS 3357 under AS9100D or ISO 9001:2015 quality systems, with full lot traceability, material certifications, and test reports for tensile, elongation, durometer, and compression set.

ElastaPro is AS9100D and ISO 2001:2105 certified. We make AMS silicone in solid sheets and uncured compounds. Contact us for more information.