As a type of anaerobic adhesive, retaining compounds are essential for the precision assembly of press- and slip-fitted parts, as well as any component that is used within systems subject to high vibration in challenging environmental conditions. Capable of filling spaces between individual components, they cure to form a strong bond and allow for the transmission of high loads without the need for air. This means sealed components and machine designs can still achieve high strength and temperature resistance across a variety of substrates.

Used across a broad range of mechanical components, as well as for bearings, shafts, and cylinder liners, retaining compounds are most commonly found within the automotive and heavy machinery industries. However, they can also be used in any industry where metal-to-metal adhesion is required for moving parts. Additionally, retaining compounds help manufacturers to avoid unnecessary machining of a broad range of mechanical components during MRO.

There are a number of reasons electrically high strength retaining compounds might be chosen over other methods of bonding and adhesion, and the advantages are clear. In fact, any type of component that will be under stress, that has a small adhesion area, and that is found within moving machinery, can benefit from retaining compounds. Moreover, any component that is at risk of fretting leading to corrosion can benefit from these materials to reduce wear and potential failure during operation.

Advantages of LOCTITE® Retaining Products:

LOCTITE® Retaining Products Offer:

• Higher strength with simplified and less costly designs
• Reduced dependence on machining tolerances
• Corrosion and fretting prevention
• Even load and stress distribution over the joint

LOCTITE® 638 is a high strength, fast curing, general purpose retaining compound.
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.

• High temperature resistance
• Tolerates minor contaminants, including industrial oils
• High strength on all metals, including passive substrates (e.g. stainless steel)
• Ideal for shafts, gears, pulleys and similar cylindrical parts
• P1 NSF Reg. No.: 123010
• DVGW Approval (EN 751-1): NG-5146AR0619
• WRAS Approval (BS 6920): 0511518

FAQ
Q: If anaerobics cure in the absence of air, how come they don’t cure in the sealed bottle?
A: The anaerobic bottles are specially formulated oxygen-permeable polyethylene bottles that allow air to pass through the wall of the bottle to maintain stability of the liquid product inside the container. The bottle is also not filled to the top for stability purposes. A 10 ml bottle does indeed contain 10 ml’s of product in a larger bottle, and a 50ml bottle does indeed contain 50ml’s of product in a larger bottle.