ND Patch®


ND Patch is a pre-applied process which fuses a nylon threadlocking coating to internal or external threads of fasteners making them self-locking and self-sealing (also known as a prevailing torque type fasteners). ND Patch fasteners are dry to the touch and ready for immediate use and unlike reactive thread lockers, require no cure time after installation.

How it Works

During the ND Patch pre-applied process, fasteners are heated and sprayed with a custom nylon powder which adheres to the part. When assembled with a mating part, the engineered plastic nylon patch is compressed.  Due to the elastic memory it resists this compression and acts like a wedge, increasing the metal to metal contact 180° opposite the material. This mechanical force creates a strong, yet fully adjustable lock which will not weaken, even under extreme vibration.



ND Patch pre-applied fasteners can be repeatedly installed and removed without damage to threads. ND Patch fasteners are particularly resistant to deformation, which makes it ideal for reuse.

Chemical Resistant

The nylon applied in ND Patch processing will not dry, shrink, or lose resiliency when exposed to commercial solvents, alcohol, gasoline, oil, caustic soda, jet fuel, etc.

Resists hi/low temps

Meets and exceeds IFI Specifications 124 & 524 as well as Military specification MIL-DTL-18240F, Type P, for temperatures from -70°F (-56°C) to +250°F (121°C).

Retains Strength

The ND Patch process involves no drilling or milling, so there is no loss of fastener strength or hardness and no troublesome burrs or chips.

Improved Sealing

Nylon is typically applied 90° which helps prevent gas and fluid leakage along the thread helix. However sealing functionality can be increased by completely coating the fastener 360°.

Proven Product

ND Patch is one of the oldest and most popular pre-applied threadlocking processes on the market. When female fasteners are coated, they function as an excellent alternative to nylon insert lock nuts.

Pre-Applied Benefits

  • Saves Time: Pre-Applied ND Patch fasteners can be automatically fed through standard feeding devices and require no cure time after installation.
  • Saves Money: Eliminates the need for costly lock washers, cotter pins, or castellated nuts. Moreover, ND Patch is less expensive than applying bottled threadlockers at the point of assembly.
  • Quality Control: Pre-Applied parts are coated to specification, ensuring consistent performance unlike bottled products. ND Patch application area and torque can be customized to meet specific needs.
  • Operator Friendly: ND Patch reduces fatigue by greatly reduces the need for re-tightening. Is also non-toxic and safe to handle.
  • Increased Margins: Add value to your fasteners without adding to inventory by supply customers with self-locking fasteners.
  • Easy to use: Works on a wide range of material finishes

Processing Notes

  • Nylon material normally positioned one to three threads back from the end of the fastener to assure ease of starting.
  • The normal coating length of the nylon patch is four to six threads. Special Patch location and coating length can be specified for specific applications.
  • Indefinite on part life under ideal storage conditions [+40°F (+4°C) to +90°F (+32°C)], but re-certification must occur once a year.
  • All fasteners should be from the same lot to ensure consistent induction heating during the application process.
  • To adjust for torque generated by patch, see the chart here.

ND Patch Competes With

  • Nylok® Blue Patch™
  • Nylok® Tuflok™
  • Nylok® Torq-Patch® Lock-Nut
  • Forest City Technologies Astorlok™
  • Forest City Tecnologies Eslok®
  • Bradley Coatings® Nylon Patch

Nylok® and Torq-Patch® are registered trademarks and Tuflok™ and Blue Patch™ are trademarks of Nylok LLC, USA. Eslok® is a registered trademark of Fitz Aerospace LLC, USA.


Steering Columns, Engine Applications, Brakes, Rear-End, Transmissions, Areas of Vibration, Areas of Heat, Military Fasteners, Snowboard / Ski binding mounting screws.

Patch Reusability Test

Compatible Fasteners

External Threads:Internal Threads:Rivets:
Banjo Bolts, Hex Bolts, Flange Bolts, Wheel Bolts, Machine Screws, Cap Screws, Wood Screws, Sheet Metal Screws, Self Drilling Screws, Shoulder Bolts, Tube Nuts, Fully Threaded Studs, Double Ended Studs, Singled Ended Studs, Press-In Captive Studs, Carriage Bolts, Lag Bolts, Socket Screws, Set Screws, Eye Bolts, Eye Lags, J-Bolts, U-Bolts, Elevator Bolts, Hangar Bolts, Perforated Base Studs, Through Hole Weld Studs.Flange Nuts, Hex Body Clinch Nuts, Prevailing Torque Nuts, Floating Nuts, Hollow Bolts, Insert Nuts, Lock Nuts, Weld Nuts, Barrel Nuts, Chicago Bolts, Jam Nuts, Wing Nuts, Square Nuts, Self-Locating Projection Weld Nuts (WN/WNS), Spot Weld Nuts, Projection Weld Nuts, Bridge Spot Weld Nuts, Tab Spot Weld Nuts, Square Projection Weld Nuts, Flange Weld Projection Nuts, Stamped Flange Weld Nuts, Spot Weld Cage Nuts.N/A

Don’t see your parts on this list? We process thousands of different types of fasteners and depending on the quantity will gladly look at whether we can accommodate yours as well.

Technical Data

ProductColorReusabilityLead ThreadsCoating LengthHardness Salt Spray ResistanceTemp MinTemp Max
ND Patch (Nylon)Yellow (other colors available)5 Cycles1 to 34 to 6 ThreadsShore D 70-80*1,000+ hours**-70°F (-57°C)250°F (120°C)

*(ASTM D2240) **ASTM B117 (X scribe)


Particular formulations of ND Patch meet or exceed the performance requirements of the following specifications and/or standards:

Spec ForSpec NumberND ProcessND Material
Bendix (Allied Signal)UI-146ND PatchND Patch (Nylon)
Bendix (Allied Signal)WI-287ND PatchND Patch (Nylon)
Case IHBM-050ND PatchND Patch (Nylon)
Caterpillar1E2511ND PatchND Patch (Nylon)
Clark Equipment81D-82DND PatchND Patch (Nylon)
Clark Equipment95G-96GND PatchND Patch (Nylon)
Dana613ND PatchND Patch (Nylon)
DanaES-0226ND PatchND Patch (Nylon)
Detroit Diesel9S240ND PatchND Patch (Nylon)
DINDIN 267 Part 15ND PatchND Patch (Nylon)
DINDIN 267 Part 28ND PatchND Patch (Nylon)
Eaton205372ND PatchND Patch (Nylon)
Fiat ChryslerPF-4730ND PatchND Patch (Nylon)
Fiat ChryslerPF-5077ND PatchND Patch (Nylon)
Fiat ChryslerPF-5144ND PatchND Patch (Nylon)
Fiat ChryslerPF-5461ND PatchND Patch (Nylon)
Fiat ChryslerPF-5683ND PatchND Patch (Nylon)
Fiat ChryslerPF-6157ND PatchND Patch (Nylon)
Fiat ChryslerPF-6158ND PatchND Patch (Nylon)
FordES-21002-S100ND PatchND Patch (Nylon)
FordES-378813-S100ND PatchND Patch (Nylon)
FordES-382101-S100ND PatchND Patch (Nylon)
FordES-N800688-S100ND PatchND Patch (Nylon)
FordWA 970ND PatchND Patch (Nylon)
General MotorsGM6189PND PatchND Patch (Nylon)
General MotorsGMW16722ND PatchND Patch (Nylon)
IFIIFI-100 (NUTS)ND PatchND Patch (Nylon)
IFIIFI-107 (NUTS)ND PatchND Patch (Nylon)
IFIIFI-124 (INCH)ND PatchND Patch (Nylon)
IFIIFI-155 (NUTS)ND PatchND Patch (Nylon)
IFIIFI-524 (METRIC)ND PatchND Patch (Nylon)
IFIIFI-555 (NUTS)ND PatchND Patch (Nylon)
John DeereJDT 905ND PatchND Patch (Nylon)
Kelsey-HayesB-3736ND PatchND Patch (Nylon)
Mack Truck10AMS1ND PatchND Patch (Nylon)
Mack Truck3/6AXS5ND PatchND Patch (Nylon)
Meritor (Rockwell)Q-70ND PatchND Patch (Nylon)
NavistarNOUN CODE 0810ND PatchND Patch (Nylon)
New Process GearPS-616ND PatchND Patch (Nylon)
Outboard Marine (OMC)#1767ND PatchND Patch (Nylon)
US MilitaryMIL-DTL-18240FND PatchND Patch (Nylon)
US MilitaryMIL-F-18240END PatchND Patch (Nylon)
US MilitaryQPL-18240-33ND PatchND Patch (Nylon)

Safety, Technical & Process Data Sheets

Process NameMaterialSafety Data Sheet (Applied)Technical Data Sheet (Applied)Process Data Sheet
ND Patch®ND Patch (Nylon)ND3141ND Patch - TDS (Applied)ND Patch - PDS
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