Nylon patch is a pre-applied thread locking coating (typically Nylon), which is fused to internal or external threads of a screw. This  patch is dry to the touch and ready for use right out of the box.

Convenience and Reliability:

• Fasteners with pre-applied threadlock are ready for assembly
• Increases productivity on assembly lines with precise thread coverage every time
• 4 years of shelf life under proper storage conditions
• Dry-to-touch, non-tacky finish, non-toxic, and assembler-friendly
• Suitable for temperatures ranging from -58°F to 300°F (-50°C to 150°C)

• Ideal for automated assembly, replacing washer and manual dispensing on production line.

Advantage of a pre applied patch over using thread locking adhesives during assembly.

Perhaps the biggest advantage of preapplying thread-lockers is simply that engineers can be certain the adhesive will actually be on the fastener, in the correct amount and in the correct location. When line personnel apply liquid adhesives during assembly, the process is prone to error. The adhesive may not get dispensed on some fasteners, or it might not be applied in the right spot.

Similarly, with preapplied thread-lockers, engineers can be sure their torque specifications will be met, because the amount of adhesive applied to each fastener will be carefully controlled.

Lastly, preapplying a thread-locker saves assemblers time and money. Liquid adhesives often need a primer to stick to the metal surface of a fastener. The preapplication process eliminates this step. Moreover, every drop of liquid adhesive costs money-and not just for the material itself. Assemblers also need to factor in the cost of waste, dispensing equipment, and cleaning and maintenance.

Nylon patch screw is commonly known as a prevailing torque type self-locking fastener.

Available readily in many screw types and sizes.