Nylon Jam Lock Nuts in Zinc Plated Steel

Thin Lock Nuts with a Nylon Insert Stopper

A nylon insert lock nut is hex-shaped, internally threaded with a nylon insert or collar. The nylon material prevents loosening from vibration by increasing friction between the nylon and the screw thread. The insert deforms elastically over the threads of the screw, but threads are not cut into the nylon. This lock nut style is also referred to as a nyloc or nylock nut, polymer insert lock nut, or elastic stop nut.

The nylon insert locks the nut in two ways. First, it forces the bottom face of the screw threads against the nut threads' top face, increasing the friction between them. Second, the nylon applies a compressive force against the screw itself. Nylon lock nuts can maintain this locking ability up to 250 °F or 121 °C.

Nylon lock nuts are not made to be backed-off after being applied. Attempting to do so creates cross threads that stop the nut from backing off the fastener.

Nylon Jam Nuts

A Nylon Jam Lock Nut, or just nylon jam nut, is a low profile version of the traditional nylon lock nut. They are ideal for applications requiring a more compact installation.

Zinc Plated Steel

Zinc is by far the most common and economical type of plating for fasteners. The zinc plating adds a protective "sacrificial" top layer against corrosion while also adding a shiny finish to the fastener. Zinc plating is ideal for indoor use where it won't be constantly exposed to harsh elements.

Nut Size
Width Across Flats
Thickness
#4
Max 0.251 - Min 0.243 Max 0.124 - Min 0.094
#6 Max 0.313 - Min 0.305 Max 0.140 - Min 0.110
#8 Max 0.345 - Min 0.336 Max 0.187 - Min 0.157
#10 Max 0.376 - Min 0.367 Max 0.187 - Min 0.157
1/4" Max 0.439 - Min 0.430 Max 0.218 - Min 0.188
5/16" Max 0.502 - Min 0.492 Max 0.265 - Min 0.235
3/8" Max 0.564 - Min 0.553 Max 0.281 - Min 0.251
7/16" Max 0.627 - Min 0.615 Max 0.328 - Min 0.298
1/2" Max 0.752 - Min 0.741 Max 0.328 - Min 0.298
9/16"
Max 0.877 - Min 0.865 Max 0.374 - Min 0.344
5/8" Max 0.940 - Min 0.928 Max 0.406 - Min 0.376
3/4" Max 1.064 - Min 1.052 Max 0.421 - Min 0.391
7/8"
Max 1.252 - Min 1.239 Max 0.484 - Min 0.454
1"
Max 1.440 - Min 1.427 Max 0.578 - Min 0.516
1-1/8"
Max 1.627 - Min 1.614 Max 0.672 - Min 0.610
1-1/4"
Max 1.815 - Min 1.801 Max 0.765 - Min 0.703
1-3/8"
Max 2.008 - Min 1.973 Max 0.821 - Min 0.759
1-1/2"
Max 2.197 - Min 2.159 Max 0.828 - Min 0.766

FAQs

How does a nylon lock nut work?

Nylon lock nuts have a nylon collar inserted into a recess at the nut's top. This recess and nylon insert are slightly smaller than the outer thread diameter. The insert deforms elastically over the threads of the screw, but threads are not cut into the nylon. This elasticity causes friction between the nylon collar and the screw making the connection resistant to loosening.

Which way do nylon lock nuts go?

Nylon lock nuts go nylon side away from the head of the bolt or screw. The threading should be coming out of the nylon insert side of the nut as the bolt or screw is fastened.

Are Nylock nuts reusable?

Yes, nylon insert lock nuts are reusable. However, we do not recommend frequent repurposing of the same nylon lock nuts in critical connections on a given application.

What is the purpose of a Nylock nut?

Nylock nuts are economical lock nuts for applications involving vibration or motion. The nylon insert of these locking nuts helps the assembly resist loosening under the application's vibration or motion.

What is zinc plated steel?

Zinc plated steel is steel that goes through the process of adding a layer or coating of zinc to protect the steel from corrosion. The added layer of zinc sacrifices itself to keep the steel from rusting, even if the plating is damaged.

Is zinc plated steel rust proof?

No. Zinc plating adds a layer of corrosion resistance for rust protection. Still, it's a thin plating, and it's not as rust resistant as hot-dip galvanizing, which also uses a zinc top layer. While not the most corrosive resistant of materials, zinc plating is easily the most economical and commonly used.

Can zinc plated steel be used outside?

Zinc plating is not a good form of corrosive protection for outdoor use, especially near saltwater or in marine environments. For those applications, stainless steel or potentially hot-dip galvanized steel would work better. Zinc-plated steel is better for indoor use.