Address
304 North Cardinal
St. Dorchester Center, MA 02124
Work Hours
Monday to Friday: 7AM - 7PM
Weekend: 10AM - 5PM
Address
304 North Cardinal
St. Dorchester Center, MA 02124
Work Hours
Monday to Friday: 7AM - 7PM
Weekend: 10AM - 5PM

This professional gasket maker combines convenient one-part processing with excellent resistance to aging, weathering, and thermal cycling. Once cured, it forms a flexible silicone rubber that can accommodate vibration, joint movement, and differences in thermal expansion between assembled parts. Henkel identifies the product for applications reaching temperatures up to 350°C, making it a practical choice for equipment exposed to intense heat where conventional sealing materials may harden or lose flexibility.
The non-sag consistency supports controlled beads on horizontal, vertical, and irregular flange surfaces. Its copper color provides clear visual confirmation during application. The sealant also provides electrical insulating performance, allowing it to support selected electrical assemblies that require a non-corrosive, heat-resistant protective seal.
Typical uses include sealing flexible flanges, timing covers, valve covers, transmission pans, thermostat housings, gear housings, access covers, and other machined or cast assemblies. It can fill surface imperfections and form a custom gasket directly between mating components. The product is recommended for metal and selected plastic substrates after application testing, especially where vibration, heat, oil exposure, or repeated temperature changes are expected.
This material is designed for gasketing and sealing rather than rigid structural bonding. Joint design, bead size, fastener torque, substrate cleanliness, and curing conditions should be validated before use in critical production or repair applications.
The uncured product has a typical specific gravity of approximately 1.05 at 22°C. Henkel reports a skin-over time of about 20 minutes and a tack-free time of approximately 20 to 60 minutes at 22°C and 50% relative humidity. After full curing, typical properties include Shore A hardness from 23 to 38, elongation of at least 350%, and tensile strength of at least 1.4 N/mm². These values are reference data rather than guaranteed purchase specifications.
Clean all mating surfaces and remove grease, oil, old gasket material, moisture, and loose contamination. Apply a continuous bead to one prepared flange, surrounding bolt holes where required. Assemble the parts within a few minutes because moisture curing begins immediately after exposure to air. Tighten fasteners according to the equipment manufacturer’s recommended sequence and torque.
Allow the sealant to cure before subjecting the assembly to heavy loads, pressure, or demanding service. Henkel suggests allowing approximately seven days when full cure is required. Wipe away excess uncured material with a suitable non-polar solvent. Store unopened containers in a dry area, ideally between 8°C and 21°C.
LOCTITE SI 5920 High-Temperature Silicone Gasket Maker offers dependable high-temperature sealing, flexible cured performance, non-corrosive chemistry, electrical insulation, and easy one-component application. It is an excellent commercial choice for automotive maintenance, industrial machinery, and heat-exposed equipment requiring a durable formed-in-place gasket.
The product is not recommended for gasoline contact, pure oxygen systems, oxygen-rich environments, chlorine, or other strong oxidizing materials. Review the latest official Henkel technical data sheet and Safety Data Sheet before qualification. Explore our high-temperature gasket makers for additional flange sealing and industrial maintenance solutions.