Permatex® 21601 Medium Strength Threadlocker BLUE, 6 ml


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SKU: 10584847
MFG: 21601


Permatex® Medium Strength Threadlocker BLUE is a medium strength anaerobic threadlocking material, which cures between engaged threads to form a unitized assembly that resists virtually all leakage, shock and vibration. The product is a single component, anaerobic liquid that cures when confined in the absence of air between close fitting metal surfaces. Ideal for all 1/4" to 3/4" diameter nut and bolt assemblies. Excellent chemical resistance with a temperature resistance range of -54 degree Celsius to +150 degree Celsius (-65 degree Fahrenheit to +300 degree Fahrenheit). Easily removable with hand tools for servicing requirements. OEM Specified. NSF White Book registered.

  • Size: 6 ml
  • OEM specified.
  • All-purpose, medium strength threadlocker
  • Ideal for all nut and bolt applications 1/4" to 3/4" (6mm to 20mm).
  • Eliminates need for stocking expensive lock nuts and lock washers.
  • Locks and seals while preventing parts loosening due to vibration.
  • Protects threads from corrosion.
  • Removable with hand tools for easy disassembly.
  • Conforms to ASTM D 5363 AN0321 (Mil-S-46163A, Type II, Grade N)
  • Tube
  • Carded.

Suggested Applications:


  • Valve cover bolts, water pump bolts, oil pan bolts, drive shaft bolts, rocker arm adjustment nuts, carburetor studs.


  • Handlebar brackets, mirror fixtures, shock bolts, rear fender nuts, small fastener nuts.


  • Valve cover bolts, water pump bolts, oil pan bolts, drive shaft bolts, rocker arm adjustment nuts, carburetor studs.

Heavy Duty

  • Case cover bolts, axle housing bolts, oil seal retainer bolts, axle shaft flange bolts, differential drain plugs, fuel tank fasteners, lug nuts, windshield wiper nuts, gear shift knobs, door hardware, running light screws, horning mounting.

Product Benefits:

  • Improved Reliability
  • Eliminates vibration issues
  • Seals against leakage
  • Prevents rusting of threads
  • Cures without cracking or shrinking
  • Can be adjusted or disassembled

Easy Application:

  • No mixing
  • No curing outside of joint
  • Thixotropic: resists dripping from threads during assembly
  • No torque compensation required during assembly

Typical Applications:

Prevents loosening and leakage of threaded fasteners. Particularly suitable for applications such as:

  • Belt tensioner bolts
  • Pulley bolts
  • Cup and core plugs
  • Fan hub bolts
  • Visor mount bolts
  • Starter mounting bolts
  • Alternator Mounting Bolts
  • Intake Manifold Bolts
  • Valve Cover Bolts
  • Vacuum Adjustment Screws
  • Oil Pan Bolts
  • Axle Cover Screws
  • Drive Shaft Bolts
  • Disc Brake Caliper Bolts
  • Gearshift Knobs

Directions For Use:

For assembly:

  • Clean all threads (Bolt and Hole) with a cleaning solvent such as Permatex® Brake and Parts Cleaner and allow to dry.
  • Determine if the threads to be bonded are Active or Inactive Metals. If material is an Inactive Metal, spray all threads with Permatex® Surface Prep and allow 30 seconds to dry . Priming is not required if the material is an Active Metal. If unknown, it is always best to use the primer.
  • Shake the product thoroughly before use.
  • To prevent the product from clogging in the nozzle, do not allow the tip to touch metal surfaces during application.
  • For Thru Holes, apply several drops of product onto the bolt at the nut engagement area. For Blind Holes, apply several drops down the female threads into the bottom of the hole. As threads are engaged, compressed air forces the product upwards into the threads.
  • Assemble and tighten as usual. When tightening to established torque values, torque compensation is not required.

For Cleanup:

  • Residual liquid films and/or fillets outside the joint are readily soluble in Permatex® Brake and Parts Cleaner.
  • Cured product can be removed with a combination of soaking in Permatex® Gasket Remover and mechanical abrasion such as a wire brush.

For Disassembly:

  • Remove with standard hand tools.
  • In the rare instance where hand tools do not work, because of excessive engagement length, apply localized heat to nut or bolt to approximately 232 degree Celsius (450 degree Fahrenheit). Disassemble while hot.

For Reassembly:

  • Remove loose product from nut and bolt.
  • Apply primer to all threads, regardless of metal type.
  • Assemble and tighten as usual.