LOCTITE AA 325 Structural Adhesive is a one-component, medium-viscosity modified acrylic adhesive engineered for bonding close-fitting rigid metal and ceramic parts. It cures at room temperature when confined between assembled surfaces and used with the recommended activator. The dark brown liquid delivers strong structural performance in demanding environments, especially where bonded components experience repeated heating, cooling, vibration, and mechanical loading.

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Key Benefits of LOCTITE AA 325 Structural Adhesive

LOCTITE AA 325 Structural Adhesive requires no resin-to-hardener mixing, helping manufacturers simplify preparation and reduce proportioning errors. The medium-viscosity formula supports controlled application on accurately fitted parts while providing enough body to remain in the intended bond area. Its activator-assisted cure system enables reliable room-temperature processing without the need for an oven, making it suitable for production lines, maintenance departments, and equipment repair operations.

The cured adhesive is designed to maintain dependable strength under thermal cycling. This characteristic is particularly useful in assemblies where metal or ceramic components expand and contract at different rates. It also offers resistance to common industrial fluids and elevated-temperature exposure under the conditions described in Henkel technical testing.

Applications for LOCTITE AA 325 Structural Adhesive

Typical uses include electric motor assemblies, magnet bonding, rigid metal component bonding, ceramic-to-metal assembly, sensor construction, appliance components, industrial machinery, and other close-fitting joints exposed to temperature changes. It is intended for structural bonding rather than flexible sealing and performs best on accurately matched surfaces with controlled bond-line gaps.

The recommended bond-line gap is approximately 0.1 mm. For larger gaps, the product can be used up to a maximum of approximately 0.5 mm when the correct activation process is followed. Because plastic substrates may be vulnerable to stress cracking, Henkel does not normally recommend this adhesive for thermoplastics unless compatibility has been confirmed through testing.

Typical Technical Properties

The uncured material is a clear, dark brown liquid with a typical specific gravity of approximately 1.1 at 25°C. Its Brookfield viscosity is listed from 14,000 to 25,000 mPa·s under the stated test conditions. When cured for 24 hours at 22°C with LOCTITE Activator 7075 applied to one surface, the adhesive develops a typical lap-shear strength of approximately 11 N/mm² on grit-blasted steel.

Henkel testing also demonstrates performance after exposure to motor oil, automatic transmission fluid, phosphate ester, gasoline, humidity, and water-glycol environments. These values are typical laboratory data rather than guaranteed purchase specifications, so users should validate the product on their actual substrates, joint design, cure process, and service conditions.

How to Apply LOCTITE AA 325 Structural Adhesive

Clean both bonding surfaces thoroughly and remove oil, grease, dust, oxide, and processing residue. Apply LOCTITE Activator 7075 or 7387 to one surface and the adhesive to the other. Assemble the parts within 15 minutes. For gaps approaching 0.5 mm or when faster curing is required, apply activator to both surfaces and assemble immediately, generally within one minute.

Hold or clamp the components until fixture strength is achieved. Remove excess uncured adhesive with a suitable organic solvent. Allow the assembly to develop full strength before applying service loads; Henkel indicates that this normally requires approximately 24 to 72 hours depending on substrate, gap, temperature, and ambient conditions.

Why Buy LOCTITE AA 325 Structural Adhesive?

LOCTITE AA 325 Structural Adhesive is a practical choice for buyers requiring a high-performance acrylic bonder for metal and ceramic components exposed to severe temperature changes. Its one-part convenience, room-temperature activator cure, controlled viscosity, fluid resistance, and proven use in electric motor assemblies support dependable industrial production.

Review the official LOCTITE AA 325 technical data sheet before qualification, and explore our industrial structural adhesives for additional bonding solutions for metal, ceramic, magnets, motors, and precision assemblies.

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