PlatSil® HTS-40 Silicone Rubber


PlatSil® HTS-40 Silicone Rubber is a high-performance, platinum-catalyzed silicone with excellent tear strength, tensile strength and elongation properties.

Molds and parts made with this silicone stand up to the rigors of high-volume production environments and repetitive demolding or stretching; common applications include concrete casting, medical modeling and training aides, and prototyping.

This room temperature curing (RTV) silicone cures to a milky white, Shore A40 rubber. PlatSil® HTS-40 is a pourable rubber, but it can be easily thickened with PlatThix Liquid Thickener or Fumed Silica for brush-on application.

Other silicones in the HTS-Series include PlatSil® HTS-25 (Shore A25) and PlatSil® HTS 25 Fast (Shore A25 hardness with a fast demold time of ~3 hours).


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Technical Specifications

Mix Ratio by Weight:
Shore Hardness:
Pour Time:
30 min.
Demold Time:
24 hr.
Cured Color:
Milky White
Mixed Viscosity:
17,000 cP
Specific Volume:
24.9 in³/lb
Specific Gravity:
831 %
Tensile Strength:
686 psi
Die B Tear Strength:
131.1 pli
Die T Tear Strength:
56.2 pli
Cure Inhibition:
Contamination from sulfur (e.g., sulfur-based clay), amines, tin compounds, cured polyester resin, some paints and some silicone rubbers may inhibit surface cure of platinum-cured rubbers.

More Information

Material Calculator

Technical Bulletin

Safety Data Sheet - Part A

Safety Data Sheet - Part B

Kit Components
PlatSil® HTS-40 Components
9-lb kit includes: 0.9 lb of PlatSil® HTS-40 Part A (~1 pint)
8.1 lb of PlatSil® HTS-Series Part B (~1 gallon)
44-lb kit includes: 4 lb of PlatSil® HTS-40 Part A (~2 quarts)
40 lb of PlatSil® HTS-Series Part B (~5 gallons)