Product Name
Permabond Anaerobic HL138 with high strength, low viscosity, general purpose, anaerobic retaining compound
Brief Description
Permabond HL138 is a high-strength, low-viscosity, general-purpose anaerobic retaining compound designed for permanently locking cylindrical assemblies such as shafts, hubs, bearings, and bushings. It cures in the absence of oxygen when confined between metal parts, forming a tough, cross-linked plastic that prevents movement, wear, pitting, and erosion.
Popular Applications & Uses
- Locking cylindrical assemblies like shafts, hubs, bearings, and bushings.- Securing gears in rotating machinery.- Retaining cylindrical components in slip, press, or shrink-fit assemblies.- Preventing wear, fretting, and loosening in high-load, high-vibration systems.- Eliminating the need for costly press fits, shrink fits, or mechanical fasteners by allowing clearance fits while increasing joint strength.- Preventing corrosion of mated parts.
Industries that Commonly Use It
- Aerospace/Defense- Automotive Service/Repair- General Manufacturing- Engineering Services- Metal Fabrication- Government & Military- Transportation/ Specialty Vehicle
Special and Unique Features
- High-strength, permanent retention.- MIL-SPEC Compliant (MIL-R-46082B Type I and ASTM D5363 Group 04, Class 1, Grade 1).- Fills small gaps (up to 0.127 mm / 0.005 in) and increases push-out force.- Fast curing at room temperature (handling strength in ~10 minutes, full cure in 24 hours).- Excellent shear strength (16 MPa / 2300 psi).- Resists wear, erosion, and corrosion.- 100% solids, solvent-free.- Low viscosity (150-300 mPa.s).- Provides 100% surface-to-surface contact, increasing load-carrying capacity more than 5 times compared to mechanical joining.
Key Properties
- Chemical composition: Acrylic.- Appearance/Color: Green.- Viscosity @ 25°C: 150-300 mPa.s (cP).- Specific Gravity: 1.1.- Maximum Gap Fill: 0.127 mm (0.005 in).- Handling Strength: ~10 minutes at 23°C (73°F).- Full Cure Time: 24 hours.- Shear Strength (Steel Collar & Pin, ISO 10123): 16 MPa (2300 psi).- Temperature Range: -55°C to 150°C (-65°F to 300°F).- Torque Strength (M10 Steel, ISO 10964): Break: 20 N·m (180 in.lb), Prevail: 36 N·m (315 in.lb).- 100% Solids, Solvent-Free.
Surface Compatibility
- Designed for use with metal parts (ferrous and non-ferrous).- Best results are obtained on clean, dry, and grease-free surfaces.- Can tolerate a slight degree of surface contamination.- Roughened surfaces (~25μm) generally give higher bond strengths.- Cure times can vary with different metals; copper and its alloys cure faster, while oxidized or passivated surfaces like stainless steel tend to cure slower.- Not recommended for use in contact with oxygen, oxygen-rich systems, and other strong oxidizing materials.- Users must check compatibility with thermoplastics.
Known backups / known substitutes
- Loctite® 638- 3M™ Scotch-Weld™ RT38- Permatex® Green Retaining Compound- ASI 41RC, ASI 35RC, ASI 40RC (from Adhesive Systems Inc.)- Permabond HM160, Permabond HM161, Permabond HM162 (other Permabond retaining compounds)- Bondloc B638, B603, B620, B641, B648 (Bondloc retaining compounds)- ResinLab RC 8000 Series (e.g., RC8003, RC8009, etc.)
Comparison Note
Permabond HL138 offers a superior, high-performance solution compared to many alternatives, providing high strength, fast cure, and compliance with military and industrial specifications. It allows for looser machining tolerances and eliminates expensive press fits by increasing joint strength through 100% surface-to-surface contact, which is significantly more effective than mechanical joining techniques.
