Loctite Vibra-Seal.
Vibra-Seal is a pre-applied, water-based thread sealant that seals and resists vibration loosening in one non-curing film. Dry to the touch on the shelf, resilient on the thread, and effective on tapered or straight threads in metal or plastic fittings. Four grades covering standard and high viscosity, NSF approval, and GM-NA automotive specifications.
Four grades. Two viscosities. Two color families.
White grades (503/503HV) are NSF-rated and plumbing-focused. Orange grades (516/517) are automotive-focused with GM-NA approvals on 516. Viscosity — low or high — is the primary selector within each color family.
503 White
NSF-approved, low-viscosity pre-applied thread sealant with constant-on torque and vibration resistance.
503HV White
High-viscosity, thixotropic pre-applied thread sealant engineered for superior gap-filling on looser thread fits.
516 Orange
High-viscosity, pre-applied thread sealant with constant-on torque and vibration resistance.
517 Orange
Low-viscosity, pre-applied orange thread sealant for both tapered and straight threads.
Seals the thread. Resists vibration. Does both at once.
The defining characteristic of the Vibra-Seal family is the combination: it seals the thread against fluid migration and provides vibration-resistant, constant-on torque in a single non-curing film. For applications where sealing is the requirement but vibration loosening is not a concern, the Dri-Seal family (350°F, NSF) is the appropriate alternative. For applications where both sealing and vibration resistance are required, and the service temperature is within 300°F, Vibra-Seal is the correct family.
Choosing between grades: select white (503/503HV) for plumbing, NSF, and general-purpose sealing. Select orange (516/517) for automotive and GM-NA specified applications. Within each color family, low viscosity (503/517) is for standard thread fits; high viscosity (503HV/516) is for looser fits and larger gaps that need gap-filling performance.
Technical & Safety Data Sheets.
| Product | Technical Data Sheet | Safety Data Sheet |
|---|---|---|
| 503 White | TDS · PDF ↗ | SDS · PDF ↗ |
| 503HV White | TDS · PDF ↗ | SDS · PDF ↗ |
| 516 Orange | TDS · PDF ↗ | SDS · PDF ↗ |
| 517 Orange | TDS · PDF ↗ | SDS · PDF ↗ |