Loctite 638

For heavy-duty assemblies requiring maximum holding power across a wide variety of metals—including passive substrates like stainless steel—this high-viscosity anaerobic retaining compound delivers dependable, permanent performance. Engineered for demanding industrial environments, it provides reliable high-temperature resistance, excellent oil tolerance, and the ability to tolerate minor surface contaminants.

Key Performance Specifications

Functionality: High-strength structural bonding for cylindrical components, dual-purpose capability for heavy-duty threadlocking and thread sealing.

Target Applications: Securing shafts, gears, pulleys, and similar rotating or load-bearing cylindrical parts.

Fixture Time: Rapid 4-minute initial cure for efficient production workflows.

Gap Filling: Accommodates diametrical clearances from 0.15 mm to 0.25 mm (0.006 in to 0.01 in).

Temperature Range: Operates reliably from -55°C to 180°C (-65°F to 355°F).

Quality Assurance: UV-fluorescent for automated inspection and quality control verification.

Compliance: Meets KIWA GASTEC QA AR 214 performance standards for metal threaded fittings used in up to 100% hydrogen gas systems