Vibra-Seal 516 Orange.
High-viscosity, pre-applied thread sealant with constant-on torque and vibration resistance. Dries to a resilient, tight-clinging film that seals against fuels, hydraulic fluids, and gases. Reusable — the joint can be readjusted or disassembled without stripping the seal. The GM-NA grade for prints calling out “Vibra-Seal.” 300°F rated.
Standard lead time 1–2 weeks — from receipt at our dock to coated parts back on yours. Rush accommodated on request. Customer pays inbound and outbound freight; F.O.B. St. Charles, IL.
REUSABLE
YES
READJUSTABLE
FUNCTION
SEAL
THREAD SEALANT
VISCOSITY
HIGH
GAP-FILLING
TEMP RANGE
300°F MAX
CONTINUOUS SERVICE
ON-TORQUE
CONSTANT
VIBRATION-RESISTANT
High-viscosity seal with constant torque, and it comes apart when you need it to.
Vibra-Seal 516 is the high-viscosity member of the Loctite Vibra-Seal pre-applied thread sealant family — engineered to seal threaded joints against fluid and gas migration, maintain consistent torque under vibration, and still allow field disassembly without destroying the seal.
The 516 formulation is a water-based sealant that dries to a resilient, tight-clinging, non-curing film on the thread surface. “Non-curing” is the key distinction from the Dri-Loc threadlocker family — where Dri-Loc grades cure anaerobically and consume the film at install, Vibra-Seal 516 remains flexible and does not undergo a permanent chemical reaction. The film seals the thread on engagement and maintains that seal through vibration and thermal cycling.
“Constant-on torque” means the fastener or fitting requires a consistent, predictable installation torque — and that torque is maintained under service conditions. The joint does not loosen under vibration. It also does not seize from over-cure, making it ideal for assemblies that need to be readjusted in the field. The high-viscosity formulation of 516 makes it particularly well suited for threads with looser fit, larger leak paths, or applications where a standard low-viscosity sealant would drain away before achieving full seal coverage.
516 is the GM-NA variant of the Vibra-Seal line — the grade domestic automotive prints specify when they call out “Vibra-Seal” without a further qualification. Engineers encountering this print callout for the first time should know: orange = 516 (high viscosity) or 517 (low viscosity). The viscosity decision drives the grade selection; both are orange, both are 300°F, and both carry the GM-NA designation. If the print specifies viscosity, the choice is made. If it does not, confirm with the engineering desk on intake.
SPEC AT A GLANCE
Why engineers reach for Vibra-Seal 516
High-viscosity pre-applied thread sealant for GM-NA automotive programs. Constant-on torque, vibration-resistant, readjustable. The orange sealant that automotive OEM prints specify as “Vibra-Seal.”
- PRODUCTVibra-Seal 516 Orange
- FAMILYLoctite Vibra-Seal
- CHEMISTRYWater-based sealant film
- VISCOSITYHigh — gap-filling
- FUNCTIONSeal (primary) · Lock (secondary)
- TEMPUp to 300°F continuous
- ON-TORQUEConstant — maintained under vibration
- OEM CONTEXTGM-NA variant for "Vibra-Seal" print callouts
- VS 517516 = high viscosity. 517 = low viscosity. Same color, same temp, same family.
- SERVICEYes — readjustable, reusable
The Loctite Vibra-Seal 516 by the numbers
The full datasheet is available below — these are the values engineers most often need before specifying. Anything missing, ask the engineering desk.
PRODUCT FAMILY
Loctite Vibra-Seal 516ORANGE
GM-NA variant of the Vibra-Seal pre-applied thread sealant family. Orange color is specified on domestic automotive prints calling out “Vibra-Seal.” High-viscosity grade — see Vibra-Seal 517 for low-viscosity alternative.
CHEMISTRY
Water-BasedNON-CURING SEALANT
Water-based sealant that dries to a resilient, tight-clinging, non-curing film. Does not cure anaerobic-style — the film remains flexible and readjustable. Resistant to most automotive fluids.
FUNCTION
Thread SealPRIMARY
Primary function is sealing — prevents fluid and gas migration through threaded joints. Secondary function is vibration-resistant locking. The joint can be disassembled and reassembled without loss of sealing performance.
VISCOSITY
HighGAP-FILLING
High-viscosity formulation — engineered for threads with looser fit or larger leak paths. The thicker film fills gaps more effectively than low-viscosity grades. Use 517 for tighter threads.
ON-TORQUE
ConstantVIBRATION-RESISTANT
“Constant-on torque” means the sealing torque is maintained consistently during installation and under vibration/thermal cycling. The joint neither loosens nor seizes under service conditions.
TEMPERATURE RANGE
Up to 300°FCONTINUOUS
Continuous-service ceiling to 300°F. Resistant to thermal cycling across the full service range. For higher temperature applications, see Loctite Dri-Seal 513 (350°F).
REUSABILITY
YesREADJUSTABLE
The non-curing film allows disassembly and reassembly. Joint can be taken apart and re-tightened in the field — a key advantage over curing threadlockers in serviceable assemblies. Film does not need to be stripped before reinstall.
SUBSTRATE
All Coating Types+ MOST PLASTICS
Works on all coating types and most plastic substrates. Broader compatibility than typical anaerobic threadlockers which require metal substrates for cure activation.
OEM APPLICATION
GM-NA"VIBRA-SEAL" CALLOUTS
The 516 is the GM-NA grade specified on domestic automotive prints that call for “Vibra-Seal.” For European programs or non-GM prints, confirm the correct grade against the print specification.
VISUAL ID
OrangeCOLOR-INSPECTABLE
Orange distinguishes Vibra-Seal 516 from the white Vibra-Seal 503/503HV grades. In production environments running multiple Vibra-Seal SKUs, orange = the GM-NA high-viscosity grade at a glance.
MANUFACTURER SPECS