3M™ Thread Sealants

ATTENTION:  3M has announced that Thread Sealant 4291 will be discontinued at the end of 2023. We recommend ND Industries ST-3 as a comparable offset.

Click Here to learn more about the performance and specifications associated with each ST-3 formulation

Authorized Applicator

ND Industries is an Authorized Applicator of 3M™ Fastener Adhesives and 3M™ Thread Sealants. 3M™ is a trademark of 3M Corporation, USA.


3M™ Thread Sealant 4291 is a water-based product designed to be pre-applied to threaded fasteners, providing excellent resistance to automotive fluids and withstanding high temperatures and pressures. Typical applications are threaded fasteners for the engine compartment.

How it Works

3M™ Thread Sealant 4291 is dry to the touch on arrival and ready for immediate assembly. During fastener installation, 4291 acts as a partial lubricant, reducing torque tension variation and preventing the galling of metals. 4291 does not harden or cure, allowing fasteners to be adjusted, removed, and replaced, if needed, during the life of the part.


High Pressure Seal

3M Fastener Sealant 4291 creates an instant seal on both straight and tapered threads.

Offers Multiple Reuses

3M Fastener Sealant 4291 is a non hardening formula with lubricating properties which makes it easy to adjust, remove, and reuse.

Resists Vibration

3M Fastener Sealant 4291 helps to lock threads by resisting vibration and thermal shock.

Environmentally Friendly

3M Fastener Sealant 4291 is a water based formula that contains no harmful Volatile Organic Compounds (VOC).

Chemical Resistant

3M Fastener Sealant 4291 exhibits excellent resistance to automotive fluids such as gasoline, motor oil, transmission fluid and anti-freeze.


3M Fastener Sealant 4291 can be used on both pipe and straight threaded fasteners.


  • Saves Time: Fasteners coated with 4291 thread sealants can be automatically fed through standard feeding devices – speeding up your process and improving productivity.
  • Saves Money: The bulk pre-application of 4291 products to fasteners is less expensive than hand applying bottled thread sealing compounds or tapes at the point of assembly.
  • Quality Control: Pre-Applied 4291 fasteners are coated to specification, ensuring consistent performance, unlike the variation from hand applying bottled products.
  • Reliability: Under most operating conditions, 4291 products are unaffected by vibration or reversal of stress and greatly reduces the need to re-tighten fasteners.


  • 3M Thread Sealant 4291 is normally applied one to three threads back from the end of a fastener to assure ease of starting.
  • Shelf life of one year from date of adhesive application, but can be as long as four years, depending on the storage conditions. Fasteners which are more than one year from the date of adhesive application should be checked for performance prior to use.
  • As with all our Pre-Applied products, ND Industries can apply 4291 to your fasteners at any one of our regional service centers, or we can supply you with completed pre-applied fasteners.

3M Thread Sealant 4291 Competes With

  • ND Industries ST-3-W
  • ND Industries ST-3-L3


Pipe Plugs, Engine Applications, Head Gasket Application, Under Head Sealant for Torque Tension control, Automotive Hose Fittings, Cooling System, A/C System

Technical Data

ProductCompetes WithChemical ResistanceFluid TightnessHigh Pressure Resistance
3M™ Thread Sealant 4291ND ST-3-W, ND ST-3-L3toluene (room temperature) No leaks
gasoline (room temperature) No leaks
motor oil (300°F/149°C) No leaks
transmission fluid (300°F/149°C) No leaks
anti-freeze (266°F/130°C) No leaks
brake fluid (300°F/149°C) No leaks
diesel fuel #2 (room temperature) No leaks
hot water (200°F/93°C) No leaks
gasoline (room temperature) 150 psi / no leaks
motor oil (300°F/149°C) 150 psi / no leaks
transmission fluid (300°F/149°C) 150 psi / no leaks
anti-freeze (266°F/130°C) 150 psi / no leaks
hot water (200°F/93°C) 150 psi / no leaks
1200+ psi (84+ kg/cm2) No leaks

Safety, Technical & Product Data Sheets

Process NameMaterialSafety Data Sheet (Applied)Technical Data Sheet (Applied)Product Data Sheet
3M™ Thread Sealant42914291 SDS
4291 - TDS (Applied)4291
Increase product quality while saving time and money with Pre-Applied adhesives and sealants.