Cures Quickly to Seal Hydraulic and Pneumatic Pipes and Fittings
Our 3M™ Scotch-Weld™ Low Viscosity Air/Hydraulic Sealant HP42 is a one-component, anaerobic sealant that cures and seals hydraulic and pneumatic pipes and fittings. This general purpose, low viscosity pipe sealant is fast-curing, sealing almost instantly. It is formulated to resist pressure and vibration as well as lock and seal medium to coarse straight and tapered threads.
Recommended Applications
- Pressure vessels
- Air compressors
- Hydraulic and pneumatic systems
Features of a Rapid Seal
Our 3M™ Scotch-Weld™ Low Viscosity Air/Hydraulic Sealant HP42 provides an almost instant low-pressure seal. A high-pressure seal results when the bond is fully cured. It seals quickly to stop leaks when applied to threads or compression fittings of most metal and certain plastic pipes, without shredding, evaporation or shrinkage. In addition, this sealant prevents galling as well as helps eliminate the waste and mess of leaking hydraulic fluids, oil, fuel and lubricants.
Formulated for Speed and Strength
Offering a rapid seal that withstands heat, pressure and vibration, 3M™ Scotch-Weld™ Low Viscosity Air/Hydraulic Sealant HP42 is an excellent solution for fast results. Resilient and durable, this pipe sealant is formulated to produce the strong seal necessary for a wide variety of demanding applications.
Understanding Anaerobic Adhesives
Anaerobic adhesives are uniquely formulated to cure in the absence of oxygen. The term “anaerobic” means “living without air” and when the oxygen is excluded, a chemical chain reaction begins that causes the adhesive to polymerize. Contact with metal speeds the polymerization process and rapidly accelerates the curing process, forming tough cross-linked plastic that provides aggressive adhesion with effective shear strength.
More commonly referred to as threadlockers, pipe sealants, retaining compounds, and gasket makers, these adhesives are often used to enhance the seal, or holding force, in the threads of joined fastener systems such as nut-and-bolt assemblies. A nut-and-bolt assembly may have as little as 15% metal-to-metal contact and even a small amount of anaerobic adhesive readily fills any air voids between the threads and then hardens to a thermoset plastic. These unique adhesives are easy-to-dispense, cure rapidly, and provide effective torque strength while resisting temperature and vibration and sealing out moisture and gasses to protect against corrosion. Anaerobic adhesives can decrease manufacturing costs, enhance equipment reliability, minimize aftermarket breakdown, and reduce warranty claims.

3M 03647, Scotch-Brite Edger Disc Pad, 7 in x .875 in, 7000133920
3M 05048, Cloth Belt 384F, 80+ XF-weight, 1 in x 12 in, Fabri-lok, Full-flex, 7100141432, 200 per case
Insize 4209-2, LONG HANDLE TELESCOPING GAGE, 1/2 ~ 3/4", 6928640311543
3M 97956, Super 77 CA Multipurpose Spray Adhesive, Low VOC <25%, Clear, 24 fl oz Can, 7100014109, 12/Case
3M™ 07012, Supplied Air Hose W-9435-100/07012(AAD), 100 ft, 3/8 in ID, Industrial Interchange Fittings, High Pressure, 7000005375, 1 EA/Case
3M 64659, Scotch-Brite Durable Flex Hand Pad, MX-HP, A/O Very Fine, 4-1/2 in x 9 in, 7100042334, 25/Carton
Dynabrade 51330 .7 hp Router, Front Exhaust, 20,000 RPM, 3/8"-24 Spindle
3M 29858, Sanding Screen, 80 grit, 12 in x 18 in, 7100161088
3M 29611, 641WY 1/4" X 24", 100 Mesh Diamond Cloth Belt, 7010534832
3M 33780, 641WY 1/4" X 24", 400 Mesh Diamond Cloth Belt, 7010534915
3M 22407, Roloc Disc 361F, 80 YF-weight, TR, 1-1/2 in, Die R150S, 7000045099
3M 15060, Roloc + Button 7, 3/8 in Red, 7000045945
Dynabrade 10690 Filter/Regulator/Lubricator, FRL40, 1/2" NPTAssy.
3M 14593, Scotch-Brite Cut and Polish Disc, 3" x 1-1/4" x 1/4" A Medium, D5, 7000045941, Box of 10
Dynabrade 79448 6" x 9" DynaBrite General Purpose Maroon Hand Pad, 20/box
3M 16556, Scotch-Brite Light Duty Hand Pad 6448B, HP-HP, 6 in x 9 in, 7010329300, 60 ea/Case
3M 13753, Scotch-Brite EXL Unitized Wheel, XL-UW, 8A Medium, 1 in x 1 in x 3/16 in, 7000148249
3M 08023, Adhesive Sealant 740 UV, White, 600 mL Sausage Pack, 7000000933, 12/Case
Air Turbine Tools 310RSV - 6mm Router Hand Tool Series with Brake, 25,000RPM, 33425
3M 11411, Roloc Disc 361F, 50 YF-weight, TR, 1 in, Die R100N, 7000045095
3M 29834, Sanding Screen, 100 Grit, 18 in x NH, 7100160819
Dynabrade 64350 26" W x 36" L (660 mm W x 914 mm L) Metal Capture Downdraft Station, 230 V (AC)
ACS Diamond Cloth Belt, CX1250 3" X 90" 20U
3M 49054, Polyurethane Sealant 540, White, 310 mL Cartridge, 7000000941, 12/Case
3M 35828, Hookit Dust Extraction Flexible Sanding Block, 406 mm x 67 mm, 7100256624
3M 71358, 641WY 1/4" X 24", 600 Mesh Diamond Cloth Belt, 7010534894
3M 53914, Performance Plus Duct Tape 8979N Nuclear Red, 48 mm x 54.8 m 12.1 mil, 7000049014, 24/ case
3M 10112, Heavy Duty Stripping Pads, 3 3/4 in x 6 in x 7/16 in, 7010290303
3M™ 72787, Calibration Kit 529-04-48, Large, 7000052154, 1 EA/Case
3M 62606, Scotch-Weld Threadlocker TL42, Blue, 50 mL Bottle, 7100039193, 10/case
3M 05209, Hookit Sanding Block D/F, 70MM x 396MM, 7000028312
3M 87179, Scotch-Weld Epoxy Adhesive 2216NS, Tan, Part B, 5 Gallon Drum (Pail), 7010309882
3M™ 72010, Replacement Filter Kit 523-01-29, 7000056891, 1 EA/Case
Standard Abrasives 724275, Buff and Blend Circle Buff GP, A/O Very Fine, 2 in x 1 Ply x 8-32, 7010368698
3M 26620, Accuspray Atomizing Head Refill Pack for 3M PPS Series 2.0,Red, 2.0 mm, 7100141414 (4 Nozzles/Kit)
Dynabrade 51812 .1 hp Straight-Line Pencil Grinder, Rear Exhaust, 1000,000 RPM, 3/32" Collet
3M 65033, Scotch-Brite Diamond Wheel, 645DC 6 in x 1/2 in x 1 in, 7010365574, Box of 3 
