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LOCTITE 515 Flange Sealant for Pumps Compressors and Rigid Metal Flanges
Ideal products for machining metal parts
Perfect sealing between parts
For gaps up to 0.25mm
LOCTITE 515 Flange Sealant for Rigid Metal Assemblies
LOCTITE 515 Flange Sealant is a one-component, high-viscosity anaerobic gasketing product developed for sealing close-fitting rigid metal faces and machined flanges. The dark-purple methacrylate gel cures when confined between assembled metal surfaces in the absence of air, forming a durable gasket that follows the exact shape of the flange. It helps fill machining marks and minor surface irregularities while maintaining direct metal-to-metal contact across the assembled joint.
Unlike conventional pre-cut gaskets, LOCTITE 515 Flange Sealant can be dispensed as a continuous bead directly onto the flange. This reduces the need to stock multiple gasket shapes and minimizes problems associated with misalignment, compression set, relaxation, or damaged paper gaskets. The material also accommodates minor flange movement after curing and provides resistance to low pressures immediately after assembly.
Key Benefits of LOCTITE 515 Flange Sealant
LOCTITE 515 Flange Sealant is designed for machined steel and aluminum components with gaps up to approximately 0.25 mm. Henkel lists a typical fixture time of around 30 minutes and a cured lap-shear strength of approximately 6 N/mm² under specified test conditions. The medium-strength cured material provides reliable sealing while supporting normal maintenance and disassembly procedures.
The uncured product has a typical specific gravity of approximately 1.1. Depending on the test speed, its published Brookfield viscosity ranges from 150,000–375,000 mPa·s to 700,000–1,700,000 mPa·s at 25°C. This highly thixotropic consistency helps the sealant remain in position during manual dispensing, automated application, or screen printing without flowing excessively away from the intended sealing path.
LOCTITE 515 Flange Sealant fluoresces under ultraviolet light, allowing operators to visually confirm bead placement during production and quality inspection. Published performance data also shows resistance after exposure to motor oil, water-glycol mixtures, diesel exhaust fluid, and gasoline under defined laboratory conditions. Actual sealing performance must be validated against the temperature, pressure, fluid, flange geometry, and operating cycle of the finished equipment.
Applications for LOCTITE 515 Flange Sealant
LOCTITE 515 Flange Sealant is commonly used as a formed-in-place gasket for pumps, thermostats, compressors, transmission housings, axle covers, gear housings, motor casings, and other close-fitting rigid metal assemblies. It is suitable for industrial manufacturing, automotive maintenance, power-generation equipment, oil and gas systems, remanufacturing, and general machinery repair.
The product is recommended primarily for steel and aluminum flanges. It is not normally recommended for thermoplastic components because stress cracking may occur. Compatibility testing should also be completed on painted, plated, coated, or chemically treated surfaces before production approval.
How to Apply LOCTITE 515 Flange Sealant
Before applying LOCTITE 515 Flange Sealant, remove oil, grease, old gasket residue, dust, moisture, and loose contamination from both flange surfaces. Dispense a continuous bead onto one flange, following the required sealing path and surrounding bolt holes where appropriate. The bead must remain continuous to avoid creating possible leakage channels.
Assemble and tighten the flanges as soon as possible to prevent the uncured sealant from creating an unintended spacing or shimming effect. Henkel permits low-pressure testing below approximately 0.05 MPa immediately after assembly to confirm that a complete seal has formed. Full operating pressure should only be introduced after the validated curing period.
Cure speed depends on substrate activity, temperature, and flange gap. Aluminum, plated metals, colder conditions, or larger gaps may cure more slowly than active steel surfaces. LOCTITE SF 7649 or SF 7471 activator can be considered when faster curing is required, but its influence on final performance should be evaluated first.
Storage and Safety of LOCTITE 515 Flange Sealant
Store LOCTITE 515 Flange Sealant in its unopened original container in a dry location, preferably between 8°C and 21°C. Do not return dispensed product to the original package. The sealant should not be used in pure oxygen, oxygen-rich systems, chlorine service, or with other strong oxidizing materials. Always review the current safety data sheet before handling.
For manufacturers and maintenance professionals seeking a reliable formed-in-place gasket, LOCTITE 515 Flange Sealant offers controlled application, UV inspection, gap filling, immediate low-pressure resistance, and durable sealing for pumps, compressors, transmissions, and rigid machined metal flanges. Explore our industrial flange sealants for additional machinery, automotive, pump, compressor, and transmission sealing solutions.
