Loctite® 640 is a high-strength, low-viscosity anaerobic retaining compound designed for bonding cylindrical fitting parts. Its slow cure time makes it ideal for applications requiring longer positioning times, such as large diameter components or assemblies involving active metals like brass.
Colour: Green
Viscosity: 450 to 750 mPa·s
Fixture Time: Approximately 2 hours on steel
Full Cure Time: 24 hours
Service Temperature Range: -55°C to +175°C
Maximum Diametrical Clearance: 0.1 mm
Shear Strength (Steel): 22 N/mm²
Fluorescence: Yes (for UV inspection)
Recommended Substrates: Steel, brass, and other active metals
Packaging Sizes: 50 ml and 250 ml bottles
Primary Chemistry:
Methacrylate ester
Loctite® 640 is formulated to provide robust bonding for cylindrical assemblies, including keys, splines, bearings, and bushings. It cures in the absence of air between close-fitting metal surfaces, forming a durable bond that resists shock and vibration. The product’s extended cure time allows for precise alignment during assembly, making it suitable for components that require careful positioning. With a fixture time of approximately 2 hours and a service temperature range of -55°C to +175°C, it delivers reliable performance in demanding applications.
Colour: Green
Viscosity: 450 to 750 mPa·s
Fixture Time: Approximately 2 hours on steel
Full Cure Time: 24 hours
Service Temperature Range: -55°C to +175°C
Maximum Diametrical Clearance: 0.1 mm
Shear Strength (Steel): 22 N/mm²
Fluorescence: Yes (for UV inspection)
Recommended Substrates: Steel, brass, and other active metals
Packaging Sizes: 50 ml and 250 ml bottles
Primary Chemistry:
Methacrylate ester
Provides reliable bonding for large diameter or complex assemblies requiring extended positioning time
Eliminates the need for mechanical locking devices, simplifying assembly processes
Prevents loosening and leakage in cylindrical assemblies due to shock and vibration
Reduces maintenance requirements by providing durable, long-lasting bonds
Ideal for bonding cylindrical parts such as keys, splines, bearings, and bushings in assemblies requiring extended positioning time
Suitable for applications involving large diameter components or active metals like brass
Effective on various metals, including less active substrates
Can be used in industries such as automotive, manufacturing, and maintenance operations where precise alignment is critical
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