Loctite 567

LOCTITE 567 is an anaerobic acrylic based thread sealant supplied as a single component, high viscosity smooth creamy paste requiring no mixing before application. The material cures when air is excluded between closely fitting metal surfaces and is specifically developed for sealing and locking tapered metal pipe threads and fittings. It provides controlled low strength locking and prevents leakage caused by vibration, mechanical shock and pressure variations. The formulation contains lubricating properties that minimize galling on stainless steel, aluminum and other metal threads. It performs effectively on both active metals such as brass and copper and passive substrates including stainless steel and plated surfaces. The product offers high temperature resistance and good oil tolerance, including resistance to minor contamination from cutting oils, lubrication fluids, anti-corrosion and protective oils. The product has received various regional approvals for use in systems handling gasoline, petroleum oils, natural gas, methane, propane and butane within specified pressure limits. It is certified for potable water systems up to 82°C and approved for certain gas applications with working pressures up to 2000 kPa and temperature range from approximately −10°C to 205°C. It has also been evaluated for hydrogen service according to recognized approval requirements. The uncured material has a specific gravity of approximately 1.1 at 23°C. Brookfield viscosity measured at 25°C using spindle 7 at 2 rpm is approximately 540,000 mPa·s, indicating a high viscosity paste consistency suitable for thread filling without excessive migration. Cure performance depends on substrate type, temperature, thread fit and the use of activators. Strength develops more rapidly at elevated temperatures and more slowly at lower temperatures. When curing on inactive metals or where gap sizes are larger, activators such as SF 7471, SF 7649 or SF 7091 may be used to accelerate strength development. Testing on various threaded assemblies shows progressive increase in breakaway and breakloose torque over time across different metals. After 4 hours at 22°C, breakaway torque on 3/8 x 24 steel bolts and nuts is at least 0.3 N·m. After 24 hours at 22°C, removal torque on 3/8 NPT steel pipe fittings pre-torqued to 27 N·m reaches approximately 50 N·m. Breakaway torque values after 24 hours at 22°C vary depending on substrate, including approximately 12 N·m on M10 black oxide steel and brass fasteners, around 8 N·m on stainless steel, about 9.3 N·m on zinc phosphate coated fasteners and approximately 2.6 N·m on zinc dichromate assemblies. Smaller and larger fasteners such as M6 and M16 show proportionate torque values according to size. Prevail torque values are lower but maintain consistent locking behavior across substrates. After one week cure at 22°C, breakloose torque on zinc phosphate fasteners pre-torqued to 5 N·m is approximately 17 N·m. The cured material has been tested for thermal and environmental resistance. Heat aging at elevated temperatures shows gradual strength variation depending on exposure duration. The product maintains functional performance at low temperatures down to −75°C. Chemical and solvent exposure testing after extended cure demonstrates good resistance to various industrial fluids when evaluated at room temperature. For assembly, threaded surfaces should be cleaned and dried before application. A continuous 360-degree bead should be applied to the leading threads of the male fitting, leaving the first thread free to avoid excess squeeze out. The material should be pressed into the threads to ensure complete void filling. For larger threads, additional product may be applied to female threads. Fittings should then be assembled and wrench tightened according to manufacturer recommendations. Properly tightened joints will provide immediate sealing against moderate pressure, while full pressure and chemical resistance are achieved after a minimum of 24 hours curing. For disassembly, standard hand tools are generally adequate. In cases of long engagement length or large diameter threads exceeding approximately 1 inch, localized heating to around 250°C may be required before removal. Cured residue can be removed using suitable solvent soaking combined with mechanical cleaning methods. The product is not recommended for use in pure oxygen or oxygen enriched systems and should not be used with strong oxidizing agents such as chlorine. Compatibility should be verified before use on thermoplastic materials. Recommended storage temperature is between 8°C and 21°C in the original unopened container. Storage below 8°C or above 28°C may negatively affect product properties. Technical values stated represent typical performance characteristics for industrial reference and users should conduct their own validation testing for specific applications.