Product category: Gasketing sealants
- Technical specifications
LOCTITE® 518 cures when confined in the absence of air between close-fitting metal surfaces. It is an anaerobic gasketing material designed for use on rigid iron, aluminum, and steel flanged mating surfaces. LOCTITE 518 fills gaps up to 0.25mm and forms a flexible, chemical-resistant seal that will not tear or decay. Parts disassemble easily, even after extended service. Typical applications include sealing close-fitting joints between rigid metal faces and flanges. It is also used as a formed-in-place gasket on rigid flanged connections, e.g. transmissions and motor housings.
Semi-flexible, medium-strength anaerobic flange gasket
For active and inactive rigid metal flanges
Cures through minor surface contamination
Adapts to flange surface irregularities and gaps up to 0.25 mm
Seals instantly against low pressure
Reduces inventory costs – no need for large inventory of cut gaskets
Resists high pressure when fully cured
No compression set or misaligned gaskets
Easy to automate
Reduces process costs – eliminates manual assembly of conventional gaskets
NSF P1 Reg. No. 123758
Rigid Assembly Gasketing,Sealing
Fixture time, Steel:
Gap fill, Unprimed:
Fluorescent,For machined, rigid flanges,Immediate Low Pressure Sealing,Strength: Medium Strength,Surface Contamination-Tolerant,Thixotropic
-55.0 °C - 150.0 °C (-65.0 °F - 300.0 °F)
Specific gravity, @ 25.0 °C:
Metal: Aluminum,Metal: Iron - Cast Iron,Metal: Passive Metal,Metal: Steel
750000.0 mPa·s (cP)
How to use
Apply LOCTITE® SF 790™ to old gasket or gasket sealants and use a wood or plastic scraper to remove residues from flange surfaces. Remove burrs. It is recommended to use LOCTITE® SF 7070™ to degrease and clean surfaces prior to applying the sealant.
If cure speed of LOCTITE® 518™ is too slow due to passive metals or low temperature (below 5°C), use LOCTITE® SF 7649™ activator. Allow to dry.
Apply a continuous bead of sealant onto one flange surface. Place the bead close to the inner rim of the flange and encircle all bolt holes. Small surface scratches will be filled by the adhesive. LOCTITE® 518™ can also be applied by roller onto larger flanges.
Assemble flanges and tighten bolts as soon as possible. Wipe away any excess squeeze-out, as this will not cure when exposed to air due to sealant's anaerobic curing properties.
Disassemble bolts with standard hand tools. Use jacking-screws, cast-on bosses or recesses to lift flanges apart. Once disassembled, apply LOCTITE® SF 790™ on old sealant and use a wood or plastic scraper to remove residues from flange surfaces.
For corroded or seized parts, use LOCTITE® LB 8040™ Freeze and Release.
Use a LOCTITE® gasketing adhesive (silicone or anaerobic depending on your application) to: completely fill voids and surface variations; replace or augment traditional gaskets; overcome typical issues of over-torqueing bolts and gasket relaxation; as well as reducing inventory with a ‘one size fits all’ solution.
Yes, Henkel anaerobic adhesives become highly resistant thermoset polymers once cured, making them suitable for a vast number of applications. Consult the online product resources or contact our technical teams for further information.
Both silicones and SMP adhesives provide excellent flexibility and gap-filling properties together with high adhesion to a wide range of substrates, making them ideal for elastic bonding & sealing applications. Silicones have superior thermal resistance for high-temperature applications whereas SMP adhesives are suitable for applications that require over-painting. There are a range of properties available for each technology type. Please speak with a Henkel representative regarding your application to determine the best available grade.
LOCTITE® silicone adhesives such as LOCTITE® SI 5920™ or LOCTITE® SI 5699™ have been specially formulated for high temperature engine sealing applications. However due to the very high temperatures generated in the combustion chamber care should be taken when specifying liquid gasketing materials around the cylinder head or exhaust manifold. Please consult the Henkel technical team for further advice where necessary.
All necessary H&S measures and PPE (personal protection equipment) requirements can be found on the product material safety data sheet, all of which are available via our website.
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