Loctite 638 retaining compound(bottle)

Loctite 638 is a high-strength, green anaerobic retaining compound specifically designed for bonding cylindrical fitting parts such as bushings, bearings, sleeves, and shafts. Where bond gaps can approach 0.25 mm and maximum strength at room temperature is required, Loctite 638 retaining adhesive is the preferred engineering solution.

This urethane methacrylate anaerobic adhesive cures on active metals and passive substrates alike, including stainless steel and plated surfaces. Loctite 638 offers outstanding high-temperature performance, oil contamination tolerance, and is Hydrogen Certified (GASTEC QA AR-214) – making it suitable for hydrogen energy applications.

Key Features & Benefits

• High strength – compressive shear strength of 29 N/mm² (4,200 psi) on steel after 72 hours
• Gap fill to 0.25 mm – ideal for worn or imprecise fits
• Works on passive substrates – stainless steel, plated surfaces, aluminium
• High temperature performance – maintains strength up to 150°C; tested to 180°C
• Oil contamination tolerance – cures through cutting, lubrication, and protection fluids
• Hydrogen Certified – GASTEC QA AR-214 approval
• UV fluorescent for easy application verification
• Cold strength tested to –75°C (-100°F)
• Fast fixture time – 13.5 N/mm² achieved in just 15 minutes on steel
• Chemical resistant to motor oil, brake fluid, ethanol, acetone, water/glycol, bio-diesel

Common Applications

Loctite 638 cylindrical retaining compound is used for:

• Locking bushings and sleeves into housings
• Retaining bearings on shafts
• Bonding gears, sprockets, and pulleys to shafts
• Repairing worn or loose interference fits
• Assemblies requiring hydrogen-safe bonding
• High-vibration industrial, automotive, and heavy equipment assemblies

How to Use Loctite 638

1. Clean all surfaces with Loctite cleaning solvent and allow to dry.
2. For large gaps or passive metals, apply Activator SF 7471™, SF 7649™, or SF 7091.
3. For slip fits: apply adhesive around the leading edge of the male part and inside the female part; use rotating motion for coverage.
4. For press fits: apply adhesive thoroughly to both surfaces and assemble at high press-on rates.
5. Do not disturb until sufficient handling strength is achieved.
6. For disassembly, apply localised heat to ~250°C.

Buy Loctite 638 retaining compound at Tapemart – bulk quantities available, fast delivery across India.