LOCTITE 571
Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other

Main features
- Medium-Viscosity Tapered-Thread Sealing
- Anaerobic One-Part Retention
- Fluid-Exposure Strength Retention
Product Description
LOCTITE 571 is a brown, medium-viscosity one-component anaerobic thread sealant for locking and sealing metal tapered threads and fittings. The methacrylate liquid cures in confined metal joints after air is excluded, with activator-supported cure available where the application process requires it. Its viscosity range supports controlled coverage without the very free flow of lower-viscosity grades. The cured sealant has medium-strength retention and measured prevailing-torque performance. Properly tightened fittings can seal immediately to moderate pressure, while a 24-hour cure supports maximum pressure and solvent resistance.
Key features
- Controlled tapered-thread coverage: A 1,000 to 10,000 mPa s viscosity supports application to metal tapered threads and fittings.
- Anaerobic one-part cure: The material cures in confined metal joints without component mixing.
- Fluid-exposure strength retention: Tested joints retained initial strength after specified 720-hour fluid exposures at 87 deg C.
Applications / Suitable for
- Locking metal tapered threads
- Sealing metal pipe fittings
- Assemblies requiring medium-strength service retention
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Thermal Properties
Physical Properties
Additional Information
As-supplied / before-processing properties
Typical values and characteristics for the product before cure, application, or assembly.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Brown liquid | - | As supplied |
| Chemical type | Methacrylate ester | - | One-component material |
| Specific gravity | 1.1 | - | 25 deg C |
| Viscosity | 1,000 to 10,000 | mPa s | Brookfield RVF, spindle 3, 20 rpm, 25 deg C |
| Cure mechanism | Anaerobic | - | Confined between close-fitting metal surfaces |
| Secondary cure support | Activator | - | When specified for the application |
After-processing / final-state properties
Typical values for the cured, bonded, treated, or in-service product under the listed conditions.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Prevailing torque after 6 h | 0.6 to 2.8 | N m | 3/8 x 24 grade 2 steel fasteners, 22 deg C |
| Prevailing torque after 24 h | 1.1 to 2.8 | N m | 3/8 x 24 grade 2 steel fasteners, 22 deg C |
| Strength retention in motor oil | 100 | % of initial | 720 h at 87 deg C |
| Strength retention in unleaded gasoline | 100 | % of initial | 720 h at 87 deg C |
| Strength retention in phosphate ester | 100 | % of initial | 720 h at 87 deg C |
| Strength retention in acetone | 100 | % of initial | 720 h at 87 deg C |
| Strength retention in distilled water | 100 | % of initial | 720 h at 87 deg C |





















