LOCTITE 638 Retaining Compound – High-Strength Bearing & Shaft Retainer

LOCTITE 638 is a high-strength anaerobic retaining compound designed to bond cylindrical metal assemblies such as bearings, bushings, sleeves, gears, pulleys, and shafts. It fills gaps between close-fitting metal parts, prevents loosening caused by vibration and shock, and restores the strength of worn assemblies. LOCTITE 638 cures in the absence of air when confined between metal surfaces, creating a durable, long-lasting bond with excellent resistance to heat, oil, and industrial chemicals.
Key Features
High-strength retaining compound for cylindrical assemblies
Ideal for shafts, bearings, bushings, sleeves, gears, and pulleys
Fills gaps up to 0.25 mm (0.01″)
High shear strength for permanent assemblies
Excellent resistance to vibration, shock, and dynamic loads
Fast curing on active metals
Resistant to oils, fuels, coolants, and industrial chemicals
Suitable for temperatures up to 180°C
Helps restore worn bearing housings and shaft assemblies
Prevents fretting corrosion and metal wear

Applications:
LOCTITE 638 is widely used in:
Bearing retention
Shaft and hub assemblies
Bushings and sleeves
Gears and sprockets
Pulleys and couplings
Electric motors
Pumps and compressors
Industrial gearboxes
Agricultural machinery
Heavy equipment maintenance
Automotive and OEM manufacturing
Technical Specifications:
Product Type: Anaerobic Retaining Compound: Color
Green: Strength
High: Gap Fill
Up to 0.25 mm
Temperature Resistance: Up to 180°C
Cure Type: Anaerobic
Suitable Materials: Steel, Cast Iron, Stainless Steel, Aluminum (with primer if required)

Benefits:
Prevents bearing movement and shaft slippage
Eliminates expensive mechanical locking methods
Reduces maintenance costs and downtime
Improves equipment reliability
Protects against corrosion and wear
Extends service life of rotating assemblies
Suitable for demanding industrial environments

Typical Industries:
Manufacturing
Automotive
Steel Plants
Cement Plants
Mining
Power Generation
Paper Mills
Textile Industry
Food Processing Equipment
Marine Engineering

How to Use:
Clean all mating surfaces thoroughly.
Apply LOCTITE 638 evenly to the shaft and bore.
Assemble the parts immediately.
Allow the adhesive to cure before placing the assembly into service.
For inactive metals or larger gaps, use an appropriate activator to accelerate curing.

Why Choose LOCTITE 638?
LOCTITE 638 provides exceptional holding power for cylindrical assemblies, making it the preferred retaining compound for industrial maintenance, equipment repair, and OEM production. Its high strength, chemical resistance, and durability ensure reliable performance even in the most demanding applications.
Frequently Asked Questions
What is LOCTITE 638 used for?
It is used to permanently retain cylindrical metal parts such as bearings, bushings, gears, sleeves, pulleys, and shafts.
Is LOCTITE 638 removable?
Yes. Because it is a high-strength retaining compound, disassembly generally requires localized heat and suitable tools.
Can it be used on stainless steel?
Yes. For faster curing on stainless steel or other inactive metals, an activator is recommended.
Is it resistant to oil and vibration?
Yes. LOCTITE 638 offers excellent resistance to oils, vibration, shock, and industrial chemicals.

Need LOCTITE 638 for your application? Contact SI Concepts today for pricing, technical guidance, and fast delivery across India.