LOCTITE® 565 thread sealant

LOCTITE 565 is an anaerobic acrylic based thread sealant supplied as a single component high viscosity paste requiring no mixing before use. The material cures in the absence of air when confined between metal threads and is intended for sealing and locking threaded pipe connections. The product provides controlled low strength locking and prevents leakage caused by vibration and mechanical stress. It has been evaluated and classified for use in systems handling gasoline, petroleum oils, natural gas, methane, propane and butane within specified pressure limits. It is also certified for potable water systems up to 82°C according to ANSI/NSF Standard 61. Pressure resistance testing has demonstrated sealing capability up to 207 bar (3000 psi) on 3/8 inch NPT steel pipe fittings assembled and cured for 24 hours prior to hydraulic testing. The uncured material has a specific gravity of approximately 1.1 at 25°C. Brookfield viscosity measured at 25°C using spindle 7 at 2 rpm ranges from 175,000 to 525,000 mPa·s. Flash point details should be referred to the Safety Data Sheet. Cure speed is influenced by temperature, substrate type, thread fit and the presence of activators. Higher temperatures accelerate strength development while lower temperatures slow the cure rate. Where cure speed is extended or inactive metals are used, activators such as 7471 or 7649 may be applied to improve curing performance. Strength development testing on steel threaded assemblies shows progressive torque build up over time at both ambient and elevated temperatures. After 72 hours at 22°C, breakaway torque on 3/8 NPT steel pipe fittings is approximately 5 N·m. After 24 hours at 22°C, breakaway torque on 3/8 x 24 steel nuts and bolts is at least 2.8 N·m, and after curing 24 hours at 93°C the value is at least 2.3 N·m. Compressive shear strength on steel pins and collars is minimum 1 N/mm². The cured material exhibits a coefficient of thermal expansion of approximately 80 × 10⁻⁶ K⁻¹, thermal conductivity of about 0.1 W/(m·K), and specific heat of approximately 0.3 kJ/(kg·K). Environmental resistance testing after 72 hours cure at 22°C shows good retention of strength after prolonged exposure to motor oil, unleaded gasoline, phosphate ester fluids, transmission fluid, brake fluid and distilled water at elevated temperatures. Heat aging at 120°C and 150°C demonstrates gradual reduction in strength depending on exposure duration. Additional testing in E85 ethanol fuel, B100 biodiesel and diesel exhaust fluid at 22°C shows maintained or increased torque retention over 500 to 1000 hours depending on the environment. For assembly, threaded surfaces should be cleaned and dried prior to application. A continuous 360 degree bead should be applied to the leading threads of the male fitting while leaving the first thread free. For larger thread sizes, product may also be applied to the female threads to ensure complete void filling. Fittings should be assembled and wrench tightened according to manufacturer specifications. Properly tightened joints provide immediate sealing to moderate pressures, while full pressure and solvent resistance is achieved after approximately 24 hours cure. For disassembly, standard hand tools are generally sufficient. In cases involving large diameters or extended engagement lengths, localized heating to approximately 250°C may be required before removal. Cured residue can be removed using appropriate solvent soaking combined with mechanical abrasion. The product is not recommended for use in pure oxygen or oxygen rich systems and should not be used with strong oxidizing agents. It is generally not recommended for thermoplastic materials unless compatibility has been verified. Recommended storage temperature is between 8°C and 21°C in the original unopened container. Storage below 8°C or above 28°C may affect product properties. Technical data provided represent typical performance values for industrial reference and users are advised to conduct suitability testing for their specific applications