Loctite 638 Retaining Compound

LOCTITE 638 Retaining Compound is a high strength anaerobic retaining compound developed for securing close-fitting cylindrical parts where maximum retention performance is required. Designed for use in confined areas between close-fitting metal surfaces, it helps prevent loosening and leakage caused by shock and vibration.

The product is intended for bonding and retaining components such as bushings and sleeves in housings, and rotors on shafts. It offers strong performance on active metals (e.g. mild steel) and is also suitable on passive substrates such as stainless steel and plated surfaces.

Key characteristics

• Technology: Acrylic (anaerobic)
• Chemical type: Urethane methacrylate
• Components: One component (no mixing)
• Cure: Anaerobic (secondary cure with activator where required)
• Strength: High
• Viscosity: High
• UV fluorescence: positive under UV light

Typical use

• Retaining bearings, bushings, and sleeves
• Securing rotors and similar cylindrical assemblies
• Applications requiring resistance to shock and vibration

For best results, use on clean, dry mating surfaces and follow the applicable application method for the assembly fit and substrate type.