Part of what makes an effective, dependable structure is knowing the piece will stay soundly intact even in the harshest environments. But to ensure reliable, lasting performance, you need the best fasteners available, and that’s where locknuts come in. And at FMW Fasteners, we offer a huge selection of locknuts that are strong, tough and durable, including zinc plated and stainless steel options.

What is a Locknut?

There are several different types of locknuts available for a range of different mechanical uses, but every variety of locknut is guaranteed to provide additional resistance to shock and vibrations that can cause loosening over time. The prevailing locknuts offered at FMW Fasteners are designed to produce better friction between the mating threads of the bolt and nut for increased resistance in any space and improved efficiency in manufacturing processes.

Locknuts are top locking with a flat bottom surface, so these fasteners are considered a one-way locknut because they can only be installed in one direction, with the top up, for effective locking results. Most locknuts are available as all-metal pieces or with a nylon insert. Locknuts are often used for:

  • Agricultural and farming equipment
  • Automotive assembly and repair
  • Metalworking industries and manufacturing locations


Different Locknuts For Sale Only at FMW Fasteners

To create project results that stand the test of time, it’s important to use locknuts when possible. Locknuts resist loosening, especially loosening related to vibration. At FMW Fasteners, we offer the widest selection of locknuts available in different materials, sizes and specifications to suit any type of assembly need.

Nylon Insert Locknuts

These locknuts have an undersized nylon ring placed in one end of the nut that stretches around the bolt for better fastening. Along with the mating threads, the nylon insert presses down on the bolt threads for even better friction and can help reduce vibration. The added nylon even provides a gas and moisture seal. Since the nylon simply forms around the threads without becoming deformed, nylon insert locknuts can be reused as needed. However, locknuts with a nylon ring should not be used in areas with temperatures exceeding 250 degrees Fahrenheit.

FMW Fasteners stocks a variety of nylon insert locknuts in different materials with exceptional performance standards. Peruse our selection of locknuts to find a solution that works best for your needs and budget. We offer:

  • Zinc plating: Locknuts with a zinc coating have an attractive shiny finish and better corrosion resistance than plain steel options. Avoid scratching or damaging the surface of the plating or the finish will be rendered useless.
  • 18-8 stainless steel: This is the most common stainless steel fastener finish with 18 percent chromium and eight percent nickel. Our 18-8 stainless steel locknuts are affordable, dependable and incredibly rust and damage resistant.
  • 316 stainless steel: Locknuts crafted from 316 stainless steel are more expensive than 18-8 stainless steel options. However, they’re made for superior performance and are highly resistant to corrosive environments. FMW Fasteners' 316 stainless steel locknuts are ideal for saltwater and chlorinated environments.


Grade 8 Nylon Insert Locknuts

When you need the sturdiest and most reliable locknuts for your application, look no further than our grade 8 steel locknuts with an added nylon insert. These locknuts are specially hardened for use in the most extreme, demanding environments like automotive suspensions.

L9 Hex Collar Locknuts

L9 hex collar locknuts are specially designed for areas with high-stress conditions. L9 provides the highest mechanical strength available and can reliably handle higher clamp loads and provide exceptional holding power over time. The hex collar locknuts are manufactured in one piece with a conical top and flat bottom with a sturdy bearing surface. What gives the hex collar locknuts improved torque is their added locking collar.

Enjoy the FMW Difference — Shop Our Locknuts Today

When you browse our selection of locknut types, you’ll find that each option is competitively priced. You can order in the amount you want, and you enjoy free shipping on all qualified orders. Also, return what you don’t want or need at any time. There’s no expiration on returns, as long as the materials remain in like-new condition.

At FMW Fasteners, we serve construction and service professionals as well as do-it-yourself enthusiasts. When you’re looking for a wide range of locknut types to choose, and when you want only the best parts to deliver the best results, trust the selection you’ll find at FMW Fasteners.