Loctite 577 thread sealant(bottle)

Loctite 577 is a medium-strength, yellow anaerobic thread sealant engineered for the locking and sealing of metal threaded pipes, fittings, and hydraulic connections. Particularly suited for stainless steel without requiring surface activation, Loctite 577 pipe sealant is a trusted solution across industrial, gas, and plumbing applications worldwide.

This single-component dimethacrylate ester cures anaerobically between close-fitting metal threads. It works on both active metals (brass, copper) and passive substrates (stainless steel, plated surfaces), offering gap performance to 0.25 mm, high-temperature resistance, and contamination tolerance. Loctite 577 is NSF Category P1 registered, EN 751-1 class H certified (DVGW), and Hydrogen Certified (GASTEC QA AR-214).

Key Features & Benefits

• Works on stainless steel without activator – no surface pre-treatment required
• NSF Category P1 – approved for food processing environments (no food contact)
• EN 751-1 Class H / DVGW Certified – for gas and hot water applications
• Hydrogen Certified – GASTEC QA AR-214 compliant
• Gap fill to 0.25 mm for thread imperfections and variations
• High thixotropic viscosity – no migration or dripping on threads
• Australian Gas Association approved – 2000 kPa rated, –10°C to 135°C
• Contamination tolerant – cures through minor surface oils
• Breakaway torque of 33 N·m on M10 steel nuts and bolts (24h at 22°C)
• Chemical resistance to DEF/AdBlue®, brake fluid, motor oil, ethanol, bio-diesel

Common Applications

Loctite 577 anaerobic pipe sealant is used for:

• Sealing metal pipe threads and hydraulic fittings
• Locking and sealing stainless steel fittings without activator
• Gas line sealing (1st, 2nd, 3rd family gases per EN 751-1)
• Potable water system thread sealing (NSF P1 approved)
• Industrial pneumatic, hydraulic, and fluid power systems
• Marine, automotive, and heavy equipment pipe connections

How to Use Loctite 577

1. Clean all surfaces with Loctite cleaning solvent and allow to dry.
2. For inactive metals or slow cure, spray with Activator SF 7471™, SF 7649™, or SF 7091™.
3. Apply a 360° bead to the leading threads of the male fitting, leaving the first thread free.
4. Force material into threads to fill voids; apply to female threads for large/wide fittings.
5. Assemble and wrench-tighten in accordance with manufacturer recommendations.
6. Allow minimum 24 hours for maximum pressure resistance and solvent resistance.

Order Loctite 577 pipe thread sealant at Tapemart – available in multiple pack sizes for industrial and trade use.