Elkem Silicone HCRA 4565 65A (HCR) High Consistency Rubber (A-4565-HCRA)

A-4565-HCRA Silicone Gum (Heat Cure HCR, Shore A 65)

A-4565-HCRA is a platinum-cure, high consistency rubber (HCR) silicone gum offering exceptional physical properties and dimensional stability. With a Shore A 65 durometer, this material provides a strong, durable elastomer ideal for applications requiring high tear strength, low shrinkage, and structural integrity.

Unlike liquid silicones, HCR materials have a gum-like consistency, allowing technicians to sculpt, shape, and laminate directly into the material before curing. This makes it especially useful for applications where control and manual forming are critical.

Processing requires a two-roll mill for proper blending, pigment incorporation, and uniform material preparation. The material offers an extended working time of up to 6 hours (at ~65°F), allowing ample time for fabrication before curing.

Cure is achieved through heat, producing a finished elastomer with excellent mechanical performance.

Product Features

• Shore A 65 high durometer silicone gum

• Platinum-cure (addition cure) system

• High consistency (gum) form for sculpting and shaping

• Excellent physical properties and durability

• Low to no shrinkage for dimensional stability

• Bonds well to various substrates for lamination

• Long working time (~6 hours at 65°F)

• Heat cure required for full vulcanization

Processing Notes

• Supplied as a two-part system (Part A & Part B)

• Mix equal parts thoroughly prior to use

• Two-roll mill required for proper blending and coloring

Typical Applications

• Sculpted silicone components

• Laminated silicone structures

• Applications requiring high strength and dimensional stability

Physical Properties (Typical)

• Durometer (Shore A): 70 (range 60–70)

• Tensile Strength: up to ~1490 psi

• Elongation: up to ~650%

• Tear Strength: up to ~214 lb/in

• Appearance: Clear

A high-performance HCR silicone designed for advanced fabrication, sculpting, and durable elastomer applications.