LOCTITE AA 325
Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other

Main features
- One-Component Adhesive System
- Rigid-Part Structural Bonding
- Gap and Fluid Resistance
Product Description
LOCTITE® AA 325™ is a one-component, medium-viscosity structural acrylic adhesive designed for bonding close-fitting rigid metal and ceramic parts. Used with a compatible activator, the clear-to-dark-brown liquid cures at room temperature when confined between mating surfaces. Typical applications include electric-motor assemblies and other components exposed to thermal cycling, with tested resistance to automotive fluids, humidity, elevated-temperature aging, and bond gaps up to 0.5 mm under specified activator conditions.
Key features
- Single-component application: Requires no adhesive mixing and cures with an activator at room temperature.
- Rigid-part structural bonding: Designed for close-fitting metal and ceramic assemblies, including thermally cycled components.
- Gap and fluid resistance: Supports bond gaps up to 0.5 mm under specified conditions and retains strength after exposure to oils, fuels, transmission fluid, coolant, and humidity.
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Additional Information
As-supplied / before-processing properties
Typical properties of the uncured material; values are reference data rather than guaranteed product specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Technology | Acrylic | — | Structural adhesive technology |
| Chemical type | Modified acrylic ester | — | Uncured material |
| Appearance | Clear to dark-brown liquid | — | TDS description; SDS confirms dark-brown liquid |
| Components | One component | — | Adhesive requires no mixing |
| Viscosity classification | Medium | — | TDS classification |
| Cure mechanism | Anaerobic with activator | — | Cures between close-fitting parts with activator |
| Cure temperature | Room temperature | — | Activator-assisted cure |
| Specific gravity | 1.1 | — | At 25°C; TDS value |
| Dynamic viscosity | 14,000–25,000 | mPa·s | Brookfield RVT, 25°C; spindle 6, 20 rpm |
| Recommended bond gap | 0.1 | mm | TDS application guidance |
| Maximum stated bond gap | 0.5 | mm | Requires activator on both surfaces and immediate assembly |
| Density | 1.1000 | g/cm³ | At 20°C; current SDS value |
| Flash point | >100 | °C | Tagliabue closed cup; current SDS |
| Auto-ignition temperature | 485 | °C | Current SDS |
| Kinematic viscosity | >20.5 | mm²/s | At 40°C; current SDS |
After-processing / final-state properties
Typical cured-material properties depend on substrate, activator, bond gap, cure time, temperature, and test method.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Coefficient of thermal expansion | 100 × 10−6 | K−1 | ISO 11359-2 |
| Thermal conductivity | 0.1 | W/(m·K) | ISO 8302 |
| Specific heat | 0.3 | kJ/(kg·K) | Typical cured material |
| Lap-shear strength | 11 | N/mm² | Grit-blasted steel; 24-hour cure at 22°C; Activator 7075 on one side |
| Lap-shear strength at 0.5 mm gap | ≥11 | N/mm² | Grit-blasted steel; 48-hour cure at 22°C; Activator 7075 on both sides |
| Unleaded-gasoline resistance | 75 | % initial strength | At 87°C; 720-hour exposure; tested at 23°C |
| Motor-oil resistance | 110 | % initial strength | 10W30 motor oil at 87°C; 720-hour exposure |
| Automatic-transmission-fluid resistance | 110 | % initial strength | At 87°C; 720-hour exposure |
| Phosphate-ester resistance | 110 | % initial strength | At 87°C; 720-hour exposure |
| Water/glycol resistance | 75 | % initial strength | 50/50 water/glycol at 150°C; 720-hour exposure |
| Humidity resistance | 75 | % initial strength | 100% RH at 50°C; 720-hour exposure |
| Heat-aging strength retention | Approx. 70 | % initial strength | Approximately 5,000 hours at 120°C; tested at 23°C; chart-derived |
| Heat-aging strength retention | Approx. 25 | % initial strength | Approximately 5,000 hours at 150°C; tested at 23°C; chart-derived |





















