Chem-Set RTV664 High-Durometer Silicone Mold Rubber (11 lb Pail Kit)

Description

The Chem-Set RTV664 silicone mold rubber is a high-durometer two-part silicone packed in an 11 pound pail kit for production tooling and short-run molds. With 62 Shore A hardness on the standard cure (and 68 Shore A available from related grades), this rubber holds shape under load, resists tear-out from sharp cores, and ships with a long enough work life to mix, deair, and pour large molds without rushing the placement. Toolmakers and prototype shops use it where a softer mold rubber would lose detail across cycles.

Where RTV664 Silicone Mold Rubber Belongs

• Production tooling for cast urethane, epoxy, and polyester parts
• High-detail molds that need stiff walls and sharp feature retention
• Manufacturing lines where chemical and abrasion resistance reduce mold replacement frequency
• Aerospace, defense, and industrial part casting where dimensional stability matters
• Long-run prototype tooling that has to outlive a softer 30 to 50 Shore A silicone

Why Shops Pick RTV664 Silicone Mold Rubber

The high durometer is the headline feature. A 62 Shore A wall stays put when a casting wants to flex it during demold, which protects fine surface detail across many cycles. Long work life lets a moldmaker mix the full pail kit, vacuum out air, and place the silicone over a complex pattern in one pass. The room temperature cure means no oven cycle is required, and the very low shrinkage keeps cavity dimensions inside spec from first pour to last.

RTV664 Silicone Mold Rubber Quick Specs

Order alongside compatible silicone mold release agents and surface activators on the Chemical Concepts industrial silicones and adhesives page. For background on RTV silicone selection, mix ratio, and cure handling, refer to manufacturer technical data published by Shin-Etsu Silicones.