PlatSil® 73-40 Silicone Rubber


PlatSil® 73-40 Silicone Rubber is a two-part, platinum-catalyzed, liquid silicone system that cures (RTV) to a yellow, Shore A40 rubber. Since PlatSil® 73-40 has no shrinkage upon curing and resists mold distortion due to casting, it is an ideal product where dimensional stability is required. This is a pourable rubber, but it can be easily thickened with PlatThix Liquid Thickener or Fumed Silica for brush-on application.


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Technical Specifications

Mix Ratio by Weight:
Shore Hardness:
Pour Time:
45 min.
Demold Time:
16 hr.
Cured Color:
Mixed Viscosity:
15,000 cP
Specific Volume:
25 in³/lb
Specific Gravity:
355 %
Tensile Strength:
465 psi
Die B Tear Strength:
52 pli
Die T Tear Strength:
7 pli
Shake or stir Part A before use.
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

Physical Properties Bulletin

Kit Components
PlatSil® 73-40 Components
1-lb kit includes: 0.1 lb of PlatSil® 73-40 Part A (~2 oz)
0.9 lb of PlatSil® 73-40 Part B (~1 pint)
44-lb kit includes: 4 lb of PlatSil® 73-40 Part A (~2 quarts)
40 lb of PlatSil® 73-40 Part B (~5 gallons)
9-lb kit includes: 0.9 lb of PlatSil® 73-40 Part A (~1 pint)
8.1 lb of PlatSil® 73-40 Part B (~1 gallon)