Hex Nuts

Standard Hexagonal Nuts For General Applications

Hex nuts, or hex finish nuts, are the most common type of finish nut used. The hexagonal shape makes these nuts easy to grasp with a wrench or pliers. These nuts are often used with screws and bolts when mechanically joining materials together. They are installed on the opposite side of the materials being fastened. With the bolt head or machine screw head on the other side, they compress the materials together for a secure fit.

Hex nuts come in an assortment of materials, platings, and coatings to fill a wide range of applications.

Stainless Steel

18-8 or 304 grades of Stainless steel are suitable for many general purpose applications, especially freshwater and non-salt water wet environments. Corrosion-resistant and durable, 18-8 stainless steel is equivalent to the A2 grade of stainless steel.

For much more corrosive environments, such as in saltwater or marine applications, 316 stainless steel is the ideal choice. 316 Stainless steel is equivalent to A4 stainless steel.

Black Oxide Coating

18-8 stainless steel hex nuts are available in a black oxide coating, which adds mild corrosion and abrasion resistance, but is mostly used for the color.

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.

Most steel grades and classes in this selection of hex nuts have a zinc plating on them. Grade 2, Grade 5, Class 8, and Class 10 steels are all zinc plated. Most Grade 8 steel is also zinc-plated. Specifically, yellow zinc plated to help Grade 8 stand out from the rest of the zinc-plated steel fasteners.

Steel Grades
  • SAE Grade 2 - Low Strength Carbon Steel
  • SAE Grade 5 - Medium Strength Carbon Steel
  • SAE Grade 8 - High Strength, Thru-Hardened Steel
  • Metric Class 8 - Comparable to Grade 5
  • Metric Class 10 - Comparable to Grade 10

Hot Dip Galvanized Steel

Hot-dip galvanizing is done by submerging the fastener in molten zinc to provide a corrosion protecting finish. Essentially, the added zinc that's applied through the galvanization process serves as a "sacrificial" layer of protection to keep the steel underneath from degrading or being damaged.

You'll find hot-dip galvanized fasteners frequently used in situations where corrosion resistance is needed without the cost of stainless steel. It is considered superior to stainless steel in terms of cost and life-cycle. For applications where the fastener will constantly be exposed to corrosive materials, you'll want to use stainless steel instead.

Note: hot-dip galvanized fasteners tend to be a little larger, with thicker threading, because of the added layer of zinc. To compensate, hot-dip galvanized nuts are tapped larger to be thread effectively on hot-dip galvanized bolts. You will have difficulty trying to fasten non-hot-dip galvanized nuts to hot-dip galvanized bolts, screws, or all thread.

Brass

Brass is an alloy made of copper and zinc. The color of brass can vary from dark to light based on the zinc content; more zinc content produces lighter brass. Brass is prized for its appearance and is often used decoratively. However, it is quite soft, so it is not suitable for all applications. Brass conducts electricity and is also a good conductor of heat.

Silicon Bronze

Silicon bronze fasteners are made of copper, silicon, and various other alloys such as zinc, tin, iron, and manganese. The color of silicon bronze may vary based on the amount of copper in the fastener.

Silicon Bronze is superior in corrosion resistance to 316 stainless steel, though it is more expensive than most fasteners. It's used in marine environments, corrosive environments, and high heat environments. Silicon bronze is similar in color to copper and is sometimes used in finish applications for the color.

Aluminum

Aluminum is a strong, durable, easily formed, and lightweight metal that is excellent for use in fasteners where strength-to-weight properties are a major requirement. Aluminum has the best strength-to-weight ratio of any metal in common use and corrosion resistance on par with stainless steel.

Chrome Plated Steel

Chrome plating is mostly known for its lustrous finish and is typically used for decorative purposes. The added plating adds an extra layer of corrosion resistance to the fastener.

FAQs

What are hex nuts?

Hex nuts are hexagonal blocks of material, typically metal, with a hole punched through that is threaded. Hex nuts, or hex finish nuts, are the most common type of finish nut used. The hexagonal shape makes these nuts easy to grasp with a wrench or pliers. These nuts are often used with screws and bolts when mechanically joining materials together.

What is a hex nut used for?

Hex nuts are used alongside machine threaded fasteners to complete a secure assembly. The head of the screw or bolt clamps down on the material while the nut clamps down on the opposite side. This effectively "sandwiches" the assembly securely together.

How does a hex nut work?

Hex nuts work jointly with machine threaded fasteners such as bolts, anchors, and machine screws to effectively clamp down on both sides of the fastened material. The bolt and nut threading causes friction against each other, allowing a secure fit for general applications. A lock nut is used instead if the application would be subject to high amounts of vibration.