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Henkel Adhesive Technologies

Henkel Adhesive Technologies

Retaining solutions

Retaining compounds reliably secure bearings, keyways and cylindrical parts into housings or onto shafts. LOCTITE® retaining compounds offer an effective and economical method to eliminate challenges such as loosening, corrosion, backlash and wearing by providing uniform stress distribution and unitizing the assembly.
A person with black gloves applying a red bottle of LOCTITE retaining compound to a cylindrical rolling bearing.
A tube of LOCTITE 660 in the foreground sitting on a table in an industrial environment.

Explore retaining compounds

LOCTITE retaining compounds are available in many different compositions and strengths to cater to a wide range of industrial applications. These different retaining compounds cover a wide variety of tolerances and applications for plant maintenance and assembly needs. Visit our e-Catalog to explore all the types of LOCTITE retaining compounds available.




Unitized assembly

By filling all airgaps, the adhesive distributes load and stress evenly over the joint.




Hours reduced

In unplanned downtime through eliminating cylindrical failure.




Assemblies retained

Leading to improved machine reliability.

Press fit bearings fail. We seal.

Gaps exists in traditional cylindrical assembly methods such as press fits and shrink fits. LOCTITE Retaining Compounds work to fill these gaps. Not only do LOCTITE Retaining Compounds significantly increase the reliability of your assemblies, but they also reduce machining and rework costs. LOCTITE Retaining Compounds unitize assemblies against vibrations and provides greater reliability. Fitted bearings fail. LOCTITE retains. Watch how LOCTITE Retaining Compounds enhance the reliability of your products & equipment, reducing failures and likelihood of future repairs and downtime.

A shaft with cylindrical bearings inside a blue centrifuge pump.

A simple gap causes mechanical fitting methods to fail

Failure of cylindrical assemblies can lead to major unplanned downtime and decreased product reliability. Many traditional retaining methods have shortcomings that lead to their failure. Pins & keyway assemblies have an uneven distribution of mass, an imbalance that can lead to vibration at high speeds. Splines and serrations cause high stresses due to the “notch effect”. Press and shrink fits rely on friction alone to transmit torque, requiring close tolerances. Most of these traditional methods involve high production costs.

LOCTITE retaining compounds are the answer

LOCTITE retaining compounds offer a reliable and cost-effective method to secure bearings, bushes, and cylindrical parts into housings or onto shafts. Because LOCTITE Retaining Compounds are applied as liquid, they fill the entire space between two close-fitting cylindrical surfaces and harden into a tough thermoset plastic, resulting in a unitized assembly. LOCTITE Retaining Compounds increase the maximum load transmission capability of the assembly and eliminate fretting corrosion and expensive machining.

A bottle of LOCTITE 638 sitting on a blue piece of machinery in an industrial environment.

LOCTITE retaining compounds vs. conventional methods

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LOCTITE vs. interference / press fits

While interference fits might seem to deliver good contact, there is only 20%-40% actual metal-to-metal contact. LOCTITE Retaining Compounds can provide 100% contact by filling the gap completely.

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LOCTITE vs. keys and splines

Keys and splines increase contact surface area, however do not completely eliminate the gaps which LOCTITE Retaining Compounds do.

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LOCTITE vs. set screws and pins

Set screws and pins lock the surfaces together, however the gaps still exists. LOCTITE retaining compounds can fill these gaps completely.

Why choose LOCTITE retaining compound solutions?

Unitize the assembly

Fills all microscopic gaps between components and increases the strength of traditional fittings.

Prevent fretting corrosion

Seals against corrosion and prevents micromovement while increasing component life.

Distribute stress uniformly

Ensures high torque transmission and eliminates failure due to stress cracking.

Fits dissimilar metals

Prevents galvanic corrosion of dissimilar metals.

Reduces cost

Allows for relaxed tolerances, reducing machining costs up to 30%.

Are easily automated

Can be applied with automated dispense equipment in production settings.

Choosing a LOCTITE retaining compound

LOCTITE Retaining Compounds are available in many different formulations to cater to a broad array of applications. They are available in liquid and semi-solid stick formulations and come in a variety of strengths, and viscosities to fill a wide range of gaps.

Explore our LOCTITE® retaining compound products and find the one that is right for your application. For more specialty products, contact us.

A group of LOCTITE retaining compound products sit on a table in an industrial setting.
LOCTITE retaining compound being applied to a cylindrical assembly.

Small Gaps

Typically, lower viscosity retaining compounds are used for gaps up to 0.006 in. These retaining compounds are used in interference fits like those found in press fits.

LOCTITE 609 is a green, high strength methacrylate ester acrylic retaining compound designed for the bonding of cylindrical fitting parts. The product cures in the absence of air between close fitting metal surfaces. Typical applications include rotor to shafts in fractional and sub fractional horsepower motors. Locks bushings and sleeves in housings on shafts.

  • Augments press fits.
  • Low viscosity.
  • Prevents loosening and leakage from shock and vibration.
LOCTITE retaining compound being applied to a cylindrical assembly.

Medium Gaps

For gaps above 0.006 in. retaining compounds with higher viscosities that allow for better gap fill are used. These include bonded slip fits or clearance fits.

LOCTITE 638 is designed for the bonding of cylindrical fitting parts, particularly with narrow bond gaps approaching 0.25 mm. The product cures when confined in the absence of air between close-fitting metal surfaces and prevents loosening and leakage due to shock and vibration. It not only works on active metals but also on passive substrates, exhibiting robust cure performance. The product offers high-temperature performance and good oil tolerance, and tolerates minor surface contaminants.

  • Tolerates minor contaminants, including industrial oils
  • High strength on all metals, including passive substrates (e.g. stainless steel)
  • High temperature resistance
  • Ideal for shafts, gears, pulleys and similar cylindrical parts
LOCTITE retaining compound being applied to a cylindrical assembly.

Worn Assemblies

For assemblies with large gaps greater than 0.020 in. that are badly worn, special paste-like retaining compounds should be used.

LOCTITE 660 is a high strength retaining compound with good gap filling properties, ideal for repairing worn-out seats, keys, splines, bearings or tapers without remaining.

  • Ideal for repairing worn parts without re-machining
  • Enables re-use of worn bearing seats, keys, splines or tapers
  • Suitable for retaining shims


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