Bolts and nuts are responsible for holding together most of the objects we use in our daily lives. Think about all the appliances, furniture, etc. that you use on a regular basis–all are held together by a variety of fasteners, both American and metric. Bolts and nuts are also a staple in most industries; from construction sites, to boat yards, to power plants, these products can be found in abundance.

Visit any online or local hardware shop and you’ll be sure to find bolts and nuts offered in a variety of styles and materials. U.S. fasteners can be manufactured in brass, bronze, zinc, stainless steel, and galvanized steel, among others. Metric fasteners generally are sold in either stainless steel and grade steel.

As aforementioned, U.S. bolts and nuts come in a variety of different materials, while metric fasteners find themselves confined to steel products only. This isn’t such a bad deal, considering stainless steel 18-8 (U.S.) and stainless A-2 (metric) have quickly been replacing brass fasteners in an array of exterior applications, such as boat building and restoration.

Another feature that sets U.S. and metric bolts and nuts apart is measurement. U.S. fasteners are measured in inches, while their metric counterparts are gauged in millimeters. Why are metric fasteners even needed in the U.S.? Because many overseas companies have American plants that use the metric system for their products.


Where to Find Bolts And Nuts

If you’re shopping for bolts and nuts, online and local mega-store or neighborhood shops are your best bet. All generally carry a healthy supply of various fasteners. It’s a good idea to know ahead of time what type of products you’re in the market for. Most applications require a specific design and size, so assessing your measurements helps your salesman.

If you’re like many of us, and don’t know the difference between fender washers and lock washers, then it’s recommended you email or call a hardware company for help. They’re experts when it comes to items like grade 5 bolts and wood screws, and can help you make the right choice. It could save you time, hassle, and cash.

Buying Bolts And Nuts Online

As the Internet has exploded, so have online fastener distributors. These companies are devoted to selling to customers, both large and small, however there is one important thing to keep in mind before settling on a particular site: customer service. Therefore, in order to be in business with a company for years to come, it’s suggested that you perform research, not only on prices, but customer care as well.

The Web provides plenty of options which is an advantage to the consumer; however, picking a company that puts its customers first can sometimes be challenging. That’s why, even if you’re in the market for something as simple as bolts and nuts, it’s always a reward to find someone who is genuinely interested in your satisfaction.

Bolt Sizes: Markings & Strength

Bolt sizes range from one fastener to the next and will ultimately depend on the specific job at hand. Bolt sizes are measured either overall or from under the head, and fall into two categories: countersunk head styles and all other head styles. For example, hex bolts are measured from under the head to the tip of the screw.

For U.S. fasteners, bolt sizes are measured in inches, while metric fasteners are measured in millimeters. Stainless steel 18-8 standard hex bolts may range from 1/4″ to 1/2″, while metric steel grade 8.8 hex bolts can vary from four mm to 16 mm in diameter.

The bolt sizes you choose will be directly tied to the strength of the materials. Say you were to select a grade 2 low to medium carbon steel bolt, at 1/4″ to 3/4″, its minimum tensile strength–the maximum load in tension pulling apart or shearing which a material can withstand before breaking or fracturing–would be a healthy 74,000 psi.

If you were looking for the strongest U.S. bolt fasteners, then grade 8 and class 10.9 steel would fit the bill. Both offer 150,000 psi on bolt sizes one inch through one and a half inches. They’re quenched and tempered, providing more bang for the proverbial buck.

Grade 8 Bolts

Made from medium carbon alloy steel, grade 8 bolts are tempered and yellow zinc plated. They’re best suited for applications where high strength and hardness is required. Available in three grades of hardness, grade 8 bolts are plated for moderate rust protection and offered in sizes ranging from 1/4″ to 1.5″.

Grade 8 Bolts are part of the family of hex bolts. They all feature a hex head and smooth shoulder area beyond the standard amount of threading. Most are offered in stainless 18-8, silicon bronze, and hot-dipped galvanized. The latter proves much more corrosion resistant than typical bolts and nuts on the market and is commonly used for exterior and coastal applications.

Grade 8 Bolts: Reliable Fasteners

Grade 8 bolts have proven time and time again that they can stand up to the toughest exterior and marine challenges thrown their way. Stainless steel 18-8 hex bolts, in particular, are highly corrosion resistant and have become the material of choice for many hardware, automotive, construction, and marine applications.

Silicon bronze grade 8 bolts have also weathered many storms and emerged flawless. An alloy of copper with greater strength and corrosion resistance than brass, silicon bronze has found itself a staple in the wood boat building and restoration industry. With grade 8 bolts it all comes down to strength, dependability, and longevity.

Hex Cap Screws

Hex cap screws, which are often referred to as hex bolts or machine bolts, feature a six-sided head with a smooth shoulder area beyond the standard amount of threading. These fasteners are available in various designs and materials. Some of the former include: standard, full thread tap bolts, grade 2 standard bolts, full thread tap bolts grade 2, grade 5 standard bolts, and grade 8 standard bolts.

Grade 5 bolts are made from medium carbon steel, tempered, and zinc plated. They’re best suited for automotive usage and other industries where supreme strength is crucial. Grade 8 bolts are made from medium carbon alloy steel, tempered, and yellow zinc plated; these dependable fasteners serve a handful of high strength applications well. It should be noted that both provide moderate rust protection and are available in three grades of hardness.

Full Thread Hex Cap Screws

Full thread tap bolts are hex cap screws that come full threaded, and are available in grade 2 and stainless steel 18-8. Full thread tap bolts grade 2 are made from low carbon steel, zinc plated, and generally used for projects that don’t require a lot of strength, such as general hardware.

It’s important to know ahead of time what degree of strength your hex cap screws need to be. When it comes to bolts and nuts, there rarely is much room for error: you can either obtain heavy duty fasteners or light weight products. If you have questions about a specific job you’re about to perform that requires said items, then it’s a good idea to contact your trusted online or local hardware company.

Partial Thread Metric Bolts

Metric bolts, a.k.a. metric hex bolts, hex cap screws, and machine bolts, come either fully or partially threaded, and are offered in a variety of materials. They’re perfect for holding virtually any exterior project together, specifically in the marine and construction industries.

Fully threaded Metric bolts have threads all the way up to the hex head; shorter lengths are always considered fully threaded. Aside from stainless steel 18.8, these metric bolts are offered in steel grade 8.8 and steel grade 8.8 fine thread. The latter is made from medium carbon steel and zinc plated, and used for general hardware, where high strength is not required.

Partial thread metric bolts feature a hex head and smooth shoulder area beyond the standard amount of threading; shorter lengths are not available with partial threading.
These fasteners offer four different materials: stainless A-2, steel grade 8.8, steel grade 8.8 fine thread, and steel grade 10.9. The stainless A-2 is an alloy bolt with high corrosion resistance and remains the material of choice for exterior and maritime applications.

Steel grade 8.8 metric bolts are made from medium carbon steel and zinc plated. They’re perfect for general hardware chores, where high strength is not required; 8.8 fine thread is used for fine and super metric thread pitches. On other hand, steel grade 10.9 is made from alloy steel quenched, tempered, and zinc plated; it’s best for automotive use and other areas where high strength is required.

Metric Fasteners

Metric fasteners feature a wide selection of hex bolts, socket screws, washers, machine screws, nuts, and pre-assembled assortments. Hex bolts, for instance, also known as hex cap screws or machine bolts, come fully or partially threaded, and are available in steel grade 8.8 and 10.9, as well as stainless steel 18-8.

Metric Fasteners, such as machine screws and socket screws, come in different styles and materials. Socket screws, specifically, also known as Allen head screws, are fastened with a hex Allen wrench. They have proven themselves time and time again to be tough and reliable indoors and outdoors, as well as in a host of different industries, including hardware, construction, and maritime.

Other Metric Fasteners

Other metric fasteners include metric nuts, which are used to attach machine thread fasteners. They can be purchased in several different styles and materials. Metric washers step up to provide a greater bearing surface under the fastener. They aid in preventing the nut, bolt, or screw from pulling through the material.

The metric fasteners category also features pre-assembled assortments. Assortments hold all of the above–bolts, screws, washers, nuts–in either metal trays or plastic boxes. When it’s all said and done, these indispensable products will be helping folks in a multitude of different industries hold their projects together for years to come.

Square Nuts

Though square nuts were once very common, they’ve found themselves gradually replaced by hex nuts. These fasteners can be used in a channel or welded into place. They’re not offered in the metric fastener category, as they are made from zinc plated steel (not stainless steel or grade steel), a material that provides moderate protection against rust.

As mentioned above, Square Nuts have been replaced by hex nuts in most applications. Like square nuts, they’re used for fastening to a bolt when mechanically joining materials together, also known as finished full. Hex nuts are made in more materials than their predecessors, such as brass, zinc, steel grade 5, steel grade 8, stainless steel 18-8, silicon bronze, and hot dipped galvanized. It all adds up to a higher degree of strength and options.

Square Nuts: Still Available

Despite hex nuts stealing their thunder, square nuts remain on the market, though not as heavily in demand as they once were. It’s possible some will soon consider this look vintage. However, your purchase of this product will all depend on your application needs.

Online and local fastener distributors carry square nuts, along with other bolts and nuts. Selecting the right company will require some research on your part, in order to locate the best price, as well as excellent customer service. For example, the product that you order might not fit your needs, so it’s essential that the people you deal with will either replace the item or provide a full refund–with a smile, of course.

Stainless Steel Screws

Stainless steel screws have quickly, and easily, become the material of choice for many industries. For instance, in recent years they have replaced brass screws as the marine industry favorite. They are incredibly corrosion resistant, standing up admirably to any element mother nature, or human nature, throws their way.

Stainless Steel Screws find themselves in virtually every category of U.S. and metric fasteners. Wood screws, hex bolts, metric machine screws, metric nuts, pan head screws, and sheet metal screws are just a few stainless steel 18-8. Moreover, they come in a variety of styles, designed to accommodate most applications.

Stainless Steel Screws: Metric Dependence

While U.S. fasteners rely on other materials, such as bronze, silicon bronze, zinc, and hot dipped galvanized, metric fasteners mainly incorporate steel and stainless steel. Therefore, no matter what type of metric fasteners you purchase, you can be assured of a product that stands up thoroughly to whatever conditions are thrown its way. Stainless A-2, equivalent to stainless 18-8, is commonly used in metric fasteners.

Stainless screws are practical for projects where high strength and low corrosion are required. For example, with more and more automobiles bolstering their performance every year, the stronger the smaller components need to be to adequately protect driver and passengers. Therefore, it’s important that fasteners offer the greatest benefit of all: safety.

Wing Nuts: Size

Wing nuts are quite possibly the coolest-looking all purpose nuts on the market. With their distinctive wings, they can be turned easily by hand. They are made from zinc plated steel and stainless steel 18-8. The latter proves to be incredibly durable and highly corrosion resistant in virtually any environment.

Wing nuts are used in a variety of industries including general hardware, construction, automotive, marine, and the list goes on and on. Wing nuts will help secure two materials together; for example, if you’re using machine screws to add another seat to your boat, wing nuts will provide less vibration and more stability. Though they can be screwed in by hand, wing nuts can also be tightened with pliers to provide more strength.

Wing nuts can be purchased easily online or at your local hardware stores in a variety of sizes. Obviously, size will matter when it comes to your respected application. Stainless steel 18-8 wing nuts, for example, range from 3/16″, to 1/2″, and can be bought in quantities of 100.

When choosing the right site, it’s important to do a bit of legwork. You want a company that’s going to be able to provide not only bolts and nuts, but satisfaction guarantees as well. Therefore, choosing a site that puts a premium on customer care and service is strongly recommended.