Loctite 648 - Retaining Compound - 50ml

LOCTITE® 648 is a high-strength, low-viscosity anaerobic retaining compound designed for securing cylindrical metal components. It is particularly suitable for retaining bearings, gears, sprockets, bushes, rotors, shafts and other close-fitting cylindrical assemblies where resistance to vibration, shock and dynamic loads is required. 

LOCTITE 648 cures when confined between close-fitting metal surfaces in the absence of air, forming a strong bond that helps prevent loosening, movement, leakage and fretting between assembled components. It is especially useful for applications where conventional press fits, keys or other mechanical retention methods may not provide sufficient security. 

Key Features

High-strength retaining compound

Low viscosity: approximately 500 mPa·s (cP)

Anaerobic curing technology

Green, fluorescent liquid

Temperature resistance: -55°C to +180°C

Fixture time on steel: approximately 3 minutes

Gap filling: up to approximately 0.15 mm

Steel shear strength: approximately 27 N/mm² (3,900 psi)

Excellent resistance to vibration and dynamic loads

Good oil tolerance

Suitable for active metals such as mild steel

Also suitable for passive surfaces such as stainless steel and plated metals

Fluorescence allows UV-based quality inspection 

Applications

LOCTITE 648 is commonly used for:

Securing bearings onto shafts

Retaining gears and sprockets on gearbox shafts

Securing rotors on electric motor shafts

Bush and sleeve retention

Shaft and hub assemblies

Cylindrical press-fit and slip-fit assemblies

Bonded heat-shrink assemblies

Preventing movement between mating cylindrical metal parts

Reducing fretting and corrosion in fitted assemblies 

Oil-Tolerant Performance

One of the useful characteristics of LOCTITE 648 is its ability to tolerate minor surface contamination from oils, including cutting fluids, lubricating oils, anti-corrosion fluids and protective fluids. Henkel nevertheless notes that excessive contamination can reduce bonding performance, so appropriate surface preparation remains important for demanding applications. 

Temperature Resistance

After curing, LOCTITE 648 has a stated operating temperature range of approximately -55°C to +180°C (-65°F to +355°F). This makes it suitable for many high-temperature industrial retaining applications where ordinary retaining compounds may not provide adequate temperature resistance. �

Henkel Adhesives

Why Use LOCTITE 648?

Unlike a conventional mechanical press fit, a retaining compound fills the microscopic clearance between mating cylindrical surfaces. This creates more uniform load distribution across the assembly and helps prevent movement, vibration-related loosening and fretting. Henkel specifically identifies LOCTITE 648 for applications requiring high strength, low viscosity and high-temperature resistance. �

Henkel Adhesives

Product Specification

Property: LOCTITE 648

Product type: Anaerobic retaining compound

Technology: Acrylic / urethane methacrylate

Colour: Green

Viscosity: 500 mPa·s (cP)

Fixture time: Approx. 3 minutes

Gap fill: Up to 0.15 mm

Shear strength on steel: Approx. 27 N/mm²

Operating temperature: -55°C to +180°C

Cure: Anaerobic

Application: Cylindrical metal assemblies

Strength: High

Oil tolerance: Yes

Fluorescent: Yes, under UV