LOCTITE 577 instantly provides a low pressure seal on taper/parallel fittings and when cured with withstand pressures in excess of 500 bar. Fittings are locked and sealed so they will not vibrate loose.

Product Characteristics

  • Higher strength on contaminated surfaces
  • Improved thermal performance
  • High performance on passive metals without an activator


  • Medium-strength, general purpose thread sealant for sealing metal threads
  • Suitable for all metals
  • Instant low pressure seal
  • Excellent chemical resistance
  • Locks connection against vibration-induced loosening and other stresses
  • Easy to apply
  • Cures on active and inactive metals
  • NSF P1 Reg. No. 123001
  • DVGW Approval (EN 751-1): DVGW Reg. No. NG-5146CQ0312

Application Examples

✓Oil tank fittings, valves, oil boilers and general use on compression fittings to guarantee a seal.
✓General use on compression fittings to guarantee a seal.

How to Apply:

  • Apply LOCTITE 577 to the leading threads of the male fitting and assemble the parts
  • Lightly tighten and align to the correct position
  • Allow to cure

Technical Data
Maximum Pipe size: 3”
Maximum Temperature: 150°C
Strength: Medium – removal with standard tools


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