LOCTITE 603 - Retaining Compound -50ml

LOCTITE 603 is a high-strength, one-component anaerobic retaining compound designed for bonding close-fitting cylindrical metal components such as bearings, bushings, shafts and sleeves. Its low viscosity makes it particularly suitable for press-fit, interference-fit and slip-fit assemblies with small clearances.

LOCTITE 603 cures when confined between close-fitting metal surfaces in the absence of air. Once cured, it forms a strong bond between the mating cylindrical surfaces, helping prevent loosening caused by shock and vibration while also reducing the risk of corrosion between the joined metal surfaces.

Key Features

High-strength retaining compound

Low-viscosity formulation

Green in color

One-component, ready-to-use adhesive

Anaerobic curing technology

Designed for close-fitting cylindrical parts

Suitable for bearings, bushings and shafts

Ideal for press and interference fits

Suitable for slip-fit assemblies with small clearances

Helps prevent loosening from shock and vibration

Helps protect against corrosion between mating metal surfaces

Oil-tolerant formulation

Gap filling capability up to approximately 0.15 mm

Operating temperature range approximately -55°C to +150°C

How LOCTITE 603 Works

LOCTITE 603 is an anaerobic retaining compound. It remains liquid while exposed to air but cures when confined between closely fitting metal surfaces where oxygen is excluded.

When applied between a shaft and bearing, bushing and housing, or similar cylindrical components, the adhesive fills microscopic surface irregularities and creates a strong bonded assembly.

This helps distribute loads more uniformly across the joint and reduces relative movement between the components.

Typical Applications

LOCTITE 603 is designed for applications involving close-fitting cylindrical metal components, including:

Bearings in housings

Bushings in housings

Shafts and hubs

Rotors and shafts

Sleeves

Press-fit components

Interference-fit assemblies

Slip-fit cylindrical components

Oil-impregnated bushings

Small electric motors

Power tools

Pumps and rotating equipment

Industrial machinery

Mechanical assemblies

Henkel specifically identifies bearings, bushings and shafts as suitable applications and lists industrial manufacturing and power tools among related applications.

Ideal for Press and Interference Fits

LOCTITE 603 can augment conventional press or interference fits by bonding the mating cylindrical surfaces.

The adhesive can help:

Increase joint reliability

Reduce movement between components

Prevent loosening caused by vibration

Improve torque transmission

Reduce the effects of minor surface irregularities

Provide additional protection against corrosion

This can allow manufacturers and maintenance teams to use adhesive retention as an alternative or supplement to purely mechanical interference-fit methods.

Bearings, Bushings and Shafts

LOCTITE 603 is particularly suited to retaining cylindrical components such as:

Bearings: Helps secure bearings into housings and prevent unwanted movement.

Bushings: Suitable for securing bushings into housings or onto shafts.

Shafts: Helps retain shafts and cylindrical components where close-fitting surfaces are available.

Rotors: Can be used for suitable rotor-to-shaft assemblies, including applications in fractional and sub-fractional horsepower motors.

Low-Viscosity Formulation

The low viscosity of LOCTITE 603 allows it to flow readily into small clearances between closely fitting cylindrical surfaces.

Henkel lists a viscosity of approximately 125 mPa·s (cP), making it suitable for applications where a low-viscosity retaining compound is required.

Its low viscosity makes LOCTITE 603 particularly appropriate for small bond gaps up to approximately 0.15 mm.

Oil-Tolerant Performance

LOCTITE 603 is identified by Henkel as an oil-tolerant retaining compound. This characteristic can be useful in maintenance and machinery applications where complete removal of minor oil contamination may be difficult.

For optimum bonding performance, however, surfaces should still be properly cleaned before application.

Technical Specifications

Property

LOCTITE 603

Product type

Retaining compound

Technology

Anaerobic acrylic

Chemical technology

Acrylates

Color

Green

Components

One-component

Viscosity

Approximately 125 mPa·s (cP)

Fixture time

Approximately 10 minutes

Gap fill

Up to approximately 0.15 mm

Operating temperature

Approximately -55°C to +150°C

Shear strength on steel

Approximately 26 N/mm² (3,770 psi)

Key characteristic

Oil tolerant

Recommended substrate

Metal, including steel

Values are typical technical values published by Henkel and can depend on substrate, gap, temperature and test conditions.

Application Procedure

1. Clean the Components

Remove dirt, grease, oil, rust and other contaminants from the mating cylindrical surfaces.

Clean surfaces provide more consistent adhesive performance.

2. Apply LOCTITE 603

Apply the retaining compound to the appropriate bonding surface. For cylindrical assemblies, ensure that sufficient adhesive is distributed around the engagement area.

3. Assemble the Components

Insert the shaft, bearing, bushing, sleeve or other cylindrical component into its mating part.

Rotate the components slightly during assembly where appropriate to distribute the adhesive evenly.

4. Allow to Cure

Allow the assembly to remain undisturbed while the adhesive cures.

Henkel lists a fixture time of approximately 10 minutes under its specified test conditions. Actual cure time can vary depending on temperature, materials, clearance and surface condition.

Advantages of LOCTITE 603

High Strength

Provides strong retention of close-fitting cylindrical components.

Low Viscosity

Flows readily into small clearances and is well suited to close-fitting assemblies.

Vibration Resistance

Helps prevent movement and loosening caused by vibration and shock.

Corrosion Protection

Helps prevent corrosion between mating metal surfaces by occupying the interface.

Oil Tolerance

Provides useful performance where minor oil contamination may be present.

Easy Application

The one-component formulation requires no mixing and can be dispensed directly from the bottle.

Reduced Mechanical Movement

Creates a bonded cylindrical interface that can reduce unwanted relative movement between components.

LOCTITE 603 vs LOCTITE 638

Both are retaining compounds, but their typical applications differ.

Feature  LOCTITE 603 LOCTITE 638

Strength High.         High

Viscosity  Low.         Higher

Typical gap: Up to ~0.15 mm.  - Larger/narrow bond gaps

Main application: Close-fitting cylindrical parts. - General cylindrical assemblies

Bearings: Excellent application - Suitable depending on fit

Bushings: Suitable.    - Suitable

Shafts: Suitable.         - Suitable

Color: Green.                - Green

Temperature range: -55°C to +150°C     -  Product-dependent

Henkel categorizes LOCTITE 603 among low-viscosity retaining compounds for small gaps, while LOCTITE 638 is positioned for cylindrical assemblies with higher viscosity and broader gap-filling capability.

Industries and Applications

LOCTITE 603 can be used in a wide range of industrial maintenance and assembly applications, including:

Electrical motors

Power tools

Pumps

Gearboxes

Rotating equipment

Mechanical machinery

Industrial equipment

Bearing assemblies

Shaft and hub assemblies

Manufacturing equipment

Maintenance and repair operations

Important Considerations

LOCTITE 603 is primarily intended for close-fitting cylindrical metal assemblies.

The product is most suitable for relatively small bond gaps.

Surface preparation has an important effect on final bond performance.

Cure speed can vary with substrate and temperature.

Passive or less reactive metal surfaces may require additional curing considerations.

For safety-critical assemblies, use the current Henkel technical documentation and equipment manufacturer's specifications.

Product selection should consider clearance, required strength, operating temperature and service conditions.

Packaging

Henkel currently lists LOCTITE 603 in 10 ml, 50 ml and 250 ml bottle sizes in its product range; actual availability and pack sizes can vary by market.

Product Summary

LOCTITE 603 is a high-strength, low-viscosity anaerobic retaining compound for close-fitting cylindrical metal parts. It is particularly suitable for bearings, bushings, shafts, press fits, interference fits and slip-fit assemblies with small clearances. Its oil-tolerant formulation, resistance to shock and vibration, and operating temperature range of approximately -55°C to +150°C make it a useful solution for industrial assembly and maintenance applications.