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Fasteners are an essential component in the construction industry. They are used to join two different components together, sometimes very heavy machinery, so knowing the proper fastener to use is necessary for safety and integrity of the project. The construction industry uses a wide variety of fasteners from corrosive resistant screws to structural bolts for heavy machinery.

Common Types of Fasteners in Construction

Screws

Screws are likely the most common fastener used in the construction industry. They are versatile for joining materials together, and the wide variety of points, thread, material, and coatings make them popular for a wide range of applications.

• Wood Screws: The coarse threads and tapered heads of wood screws make them ideal for use on hardwood surfaces.
• Deck Screws: They feature self-tapping heads and are corrosive resistant; they mimic wood screws in appearance.
• Sheet Metal Screws: Over a variety of drill points to cover a variety of applications. Used to fasten two pieces of metal.
• Tek Screws: Self Drilling screws that do not require a pilot hole when fastening.

Bolts, Nuts, and Washers

Bolts are also incredibly common in the construction industry. The variety of diameter, thread, material, strength, and finish cover every application. From low grade, Grade 2 (A307A), to structural grade ASTM A325, knowing the correct fastener for your application is critical.

Finish and Coating

Finish is also necessary when choosing your fastener. Alloy steel, Zinc Plated, Hot Dipped Galvanized, and Stainless steel are the most common platings and coatings. Depending on your application, it may be necessary to choose a fastener with corrosion resistance to ensure the integrity of the application.

Additional Fasteners

Anchors

Anchors are used to attach materials to concrete, brick, or other masonry materials. They are available in a range of sizes and styles, including wedge anchors, sleeve anchors, and concrete anchors.

Nails

Nails are used to join wood together and are available in a variety of sizes and lengths. They lack threading but come in a variety of materials for your application.

Rivets

Rivets are used to join two metal pieces together and are typically used in aircraft and other applications where a strong, permanent joint is required. As a permanent fastening, rivets are used in many different forms of construction.

Conclusion

The construction industry is certainly one of the most common industries for fastener use. To ensure that even your most critical jobs and applications are safe, it is necessary to choose the correct fastener with strength, cycle of life, and finish in mind. Kenneth G. Lilly Fasteners sells a variety of fasteners for use in the construction industry. With our years of industry expertise and trust, contact us for a quote.

When it comes to industrial applications—from large-scale construction to high-pressure equipment assemblies—fasteners are the unsung heroes that literally hold everything together. With so many types to choose from, it’s easy to get overwhelmed by terms like threaded studs, rods, hex head cap screws, or socket head screws. In this post, we’ll walk you through the basics of these common fasteners, explaining what they are, how they’re used, and what makes them different.

Threaded Studs

What They Are
A threaded stud is essentially a piece of metal rod that’s threaded on both ends (or sometimes along its full length). Unlike a conventional bolt, which has a head on one end, a stud is typically headless.

Key Advantages

• Flexibility: You can adjust the clamping length by choosing nuts and washers as needed.
• Strength: High-tension applications often call for studs rather than bolts.
• Alignment: Because there’s no head, studs are frequently used where precise alignment of components is essential.

Typical Uses

• Engine Blocks: Common in automotive and heavy-equipment applications for cylinder heads.
• Pressure Vessels: High-pressure, high-temperature environments often employ studs to achieve a secure and uniform seal.
• Flange Connections: Industrial piping and flange assemblies rely on studs to maintain robust connections over time.

Threaded Rods

What They Are
Threaded rods look similar to studs but are fully threaded throughout their entire length. Also referred to as “all-thread,” these rods can be easily cut to a custom length, making them a versatile fastening solution.

Key Advantages

• Adjustable Length: Cut to your exact specification, ideal for jobs that need custom lengths.
• Versatility: Can be paired with standard nuts and washers for various load requirements.
• Cost-Effective: Usually more affordable than specialized fasteners, especially for large-scale projects.

Typical Uses

• Infrastructure Projects: Frequently utilized in construction for suspending ceilings, HVAC systems, or supporting structural components.
• Electrical and Plumbing: Used to mount or support conduit, panels, and heavy fixtures.
• DIY and Repair Work: Popular in home or workshop settings due to their versatility.

Threaded Stud Assemblies (with Nuts)

What They Are
A threaded stud assembly is basically a stud provided with the appropriate nuts (and sometimes washers) as a complete set. This packaging ensures you have matching components—especially important where specific material grades or finishes are required.

Key Advantages

• Convenience: Everything you need in one kit, reducing the risk of mismatch.
• Quality Assurance: Guaranteed compatibility and meeting of specified standards.
• Material Consistency: Helps maintain consistent performance across multiple connection points.

Typical Uses

• High-Pressure or Temperature Applications: Where reliability is critical and parts must meet stringent specifications.
• Maintenance and Repair: Great for quick fixes or replacements, especially when you need to minimize downtime.
• OEM & Equipment Assembly: Ensures uniform parts in manufacturing lines.

Hex Head Cap Screws (Bolts)

What They Are
One of the most recognizable fasteners, hex head cap screws—often just referred to as “bolts”—feature a six-sided (hex) head and external threading. These are designed to be used with either a nut or a tapped (threaded) hole.

Key Advantages

• Ease of Use: Standard hex heads allow for straightforward tightening with wrenches or sockets.
• Variety: Available in a wide range of lengths, diameters, and materials (e.g., steel, stainless steel, alloy).
• Versatility: Used everywhere from machinery and automobiles to construction and home improvements.

Typical Uses

• Machine Assembly: Joining parts in industrial equipment, engines, and consumer products.
• Structural Bolting: In construction beams or anywhere a secure, load-bearing connection is needed.
• General Maintenance: The go-to fastener for nearly any repair task requiring robust clamping force.

Socket Head Screws

What They Are
Socket head screws have a recessed socket drive (commonly a hex or Allen drive) rather than an external head. They can come in various head styles—such as button head, flat head, or standard socket head cap screws—making them popular for tighter spaces or flush installations.

Key Advantages

• Compact Head: The recessed drive allows a cleaner, more streamlined profile.
• Torque Control: A hex or Allen key offers excellent control for torque, reducing the risk of overtightening.
• Aesthetic Appeal: Often seen in applications where a sleek, minimal protrusion is desired.

Typical Uses

• Machine Tooling: Widely used in precision equipment, jigs, and fixtures due to their compact design.
• Automotive and Motorcycle Mods: Enthusiasts often prefer socket head screws for aesthetic and practical reasons.
• Electronics and Robotics: Great for tight spaces where a traditional wrench can’t fit.

Material Considerations

Regardless of which fastener type you choose, material selection is just as critical. Common materials include:

• Carbon Steel: Affordable and suitable for many general-purpose applications.
• Alloy Steel: Provides higher strength and better heat resistance.
• Stainless Steel: Excellent corrosion resistance, ideal for applications exposed to moisture or chemicals.
• Exotic Alloys (Inconel, Monel, Titanium): Used in extreme conditions like high temperatures, high pressure, or corrosive environments.

Picking the Right Fastener for Your Needs

1. Determine the Load Requirements: Understanding the forces (tensile, shear, vibration, etc.) involved is the first step.
2. Evaluate the Environment: Factors like temperature range, exposure to chemicals, and moisture levels will guide your material choice.
3. Review Standards and Specifications: Industries such as petrochemical, power generation, and construction often mandate compliance with standards like ASTM or ASME.
4. Consult an Expert: If you’re unsure, reach out to a specialty fastener distributor who can guide you to the correct product.

Final Thoughts

From threaded studs and rods to hex head bolts and socket screws, each type of fastener has a specific purpose and set of advantages. Understanding the basics will help you select the right fastener for the job—keeping your projects safer, stronger, and compliant with industry requirements.

Looking for a reliable source of industrial fasteners? We’re here to help guide you through choosing the perfect studs, rods, or bolts to meet your exact specifications. Contact us today to learn more about our full range of high-performance fasteners and how we can support your next project!

Fasteners Cut-to-Length to Meet Your Specific Application Requirements

Our in-house customization capabilities include cutting threaded studs, threaded rod, and bolts to your specific length requirements. Commonly, our customers have specific length requirements for threaded stud assemblies that are not readily available as off-the-shelf products. Let us know your specific needs, and we'll work with you to ensure you have a rapidly deployed solution.

Grinding

We perform in-house grinding to remove excess material from fasteners after they've been cut-to-length. Additionally, this process creates a smooth finish and can shape parts to precise size and tolerances. During grinding, small pieces are shaved off until the right thickness or angle is reached. Our grinding process removes rough spots or edges to ensure there are no issues when your team is in the field installing our fasteners. Different types of grinding exist, such as surface grinding or cylindrical grinding, each designed for a certain shape or purpose. Although it can be slower than other methods, grinding delivers high accuracy and a polished look.

Chamfering

Chamfering is when we cut or file off a sharp corner to make a slanted edge. This prevents cuts or scrapes and helps parts fit together more smoothly. Many industries use chamfering on metal, plastic, or wood. For example, machines may bevel bolt ends or trim corners on metal plates. The size of the chamfer depends on the product’s needs. A small chamfer just takes off the edge, while a larger bevel might be used for a tight fit in assembly. Chamfering improves safety, makes parts easier to handle, and helps them line up during installation.

Plating

Plating adds a thin layer of metal on top of another metal surface. A common way is dipping the part in a liquid bath with metal particles. Then an electric current helps those particles stick to the part. Plating can protect the part from rust, make it stronger, or give it a shiny look. Different metals, like zinc or nickel, are used based on the job. For example, zinc plating fights corrosion, while nickel plating adds hardness. 

Let us know if you require a specific plating - from zinc to nickel, and more, we can customize a fastener to suit your needs.

Coating

Coating covers a material (often metal) with paint, powder, or another protective layer. This shields the surface from moisture, chemicals, and wear. Many coatings also add color or a smooth finish. Factories might spray the coating on, dip the parts, or use special equipment that heats powder onto the surface. Good surface prep is important so the coating sticks well. Coatings can be as simple as paint or as complex as PTFE.

ASTM A193 B7 alloy steel is commonly used in high pressure, high temperature environments because it undergoes heat treatment during manufacturing. It can withstand service temperatures up to 750 degrees F. It maintains a minimum tensile strength of 125 ksi and a minimum yield strength of 105 ksi.

Where A193 B7 is a chromium-molybdenum alloy, A193 B16 adds an element: chromium-molybdenum-vanadium.

A193 B16 has similar mechanical properties to its little brother A193 B7 (minimum tensile strength of 125 ksi and a minimum yield strength of 105 ksi). However, the addition of vanadium enables A193 B16 to withstand higher service temperatures: up to 1000 degrees F.

Both grades are available in stud bolts and hex bolts. They are marked “B7” or “B16” respectively, but B16 studs are also painted fluorescent green at the tips.

Both grades are most often used uncoated. These grades are meant for use in high pressure and high temperature environments, but not in corrosive environments. Upon request, they can be zinc plated to add some corrosion resistance, but it is important to consider Appendix X2 of the ASTM A193 specification. Zinc has a melting point of 780 degrees F. At any field temperatures more than approximately half of that melting point – so at 390 degrees F – there is an increased risk of embrittlement. That is to say, because the coating will begin to behave differently at 390 degrees F, the entire assembly is at higher risk of embrittlement significantly before the maximum temperature of 750 degrees F when used plain, without a coating.

These stud bolts and hex bolts can be coated with PTFE, but are not for use at high temperatures, so while you will frequently see PTFE coated B7, it is generally not used on B16 since B16 is used in higher temperature environments.

Grade 8 screws are equivalent to metric grade 10.9. Alloy steel socket head screws (ASTM A574) are stronger than grade 8 screws and are equivalent to metric grade 12.9.

Alloy steel is the most common grade in socket head cap screws. These socket heads are also commonly manufactured with a 3A thread fit – tighter and more precise than the 2A fit on most grade 5 or grade 8 fasteners. They are often used in blind holes in precisely machined equipment. Where grade 8’s might be removed as part of regular maintenance, socket heads are meant to resist loosening and hold strength for a longer maintenance cycle – often the entire lifecycle of the equipment.

There are various stainless steel alloys used in fasteners, but the most common are 304 and 316. 

The main alloying element in stainless steel is chromium. In fact, to be considered a true stainless steel, an alloy must contain a minimum of 10.5% chromium as it is the primary factor in what makes stainless “stain less.” 

304 stainless steel has approximately 18% chromium. It is often called “18-8” because it contains 18% chromium and 8% nickel (approximately).

316 stainless steel has about the same amount of chromium as 304 but adds more nickel and more molybdenum, increasing its overall corrosion resistance. 

Both 304 and 316 are in the category of stainless known as Austenitic which refers to the molecular structure. Stainlesses in this series (300 series) are high in chromium and nickel. Contrast that with 400 series stainless steels which are known as Martensitic and have a higher proportion of carbon. With their higher carbon content, 400 series stainless steels tend to be stronger, harder, and less ductile than 300 series stainless steels. 

Both coatings are zinc, an element that corrodes much slower than plain steel. The primary difference is that zinc plating is a thin coat (under 1 mil) and galvanizing is a thicker coat (over 1 mil). Zinc is also shinier, as it is often paired with a chromate additive. 

Zinc plating is applied most often via an electrical bath. Galvanizing on the other hand is done most often by dipping it in a bath of zinc.

This bath is what gives galvanized material a thicker coating, and it is because of this extra thickness that galvanized parts must be used with one another – the threads are cut to accommodate extra layers of coating. Without that accommodation in thread size, the coating would make the part unable to mate with other, non coated parts.

Galvanized fasteners are more corrosion resistant than zinc plated fasteners. The galvanized coating is thicker and is considered “self healing.” When it is damaged or scratched it is able to fill itself in, protecting the underlying steel. This is not the case for zinc plating. Once a zinc plating is scratched the steel beneath is exposed.

SAE grades 5 and 8 are equivalent to metric classes 8.8 and 10.9, respectively. Grade 5 and metric class 8.8 have approximately equivalent tensile strengths, and the same is true between Grade 8 and class 10.9.

It may be tempting to think of metric class 8.8 as the equivalent to the SAE grade 8. That is not the case! The metric naming system is derived from the performance of the bolts. The naming system of SAE grades is arbitrary, counting up from 1. Higher means stronger in both systems, but the similarities end there. A fun (and useful) fact about the metric convention is in what follows the decimal in the class. That is, the .8 in class 8.8 and the .9 in class 10.9. The number before the decimal corresponds to the tensile strength, and the decimal value after corresponds to the yield strength, expressed as a percentage of tensile strength. To illustrate:

Tensile strength is the point at which a bolt breaks. It’s yield comes before that. The yield is the point at which the bolt is deformed past the point that it can return to shape. Keep in mind that bolts will “stretch” while in service, but they will “bounce” back to size after each stretch, like a spring. However, at a certain point, they will get stretched too far. They will get deformed past the point of return. That is the yield point. Between the yield point and the tensile point, the bolt with elongate. It will behave like taffy or mozzarella cheese until it breaks away from its other half. Higher grades are typically harder and more brittle than lower grades. They will not experience very much “stretch” before breaking. We might think of lower grades as being weaker but also “stretchier” – after beginning to yield, they experience greater elongation than the higher strength grades before breaking. 

Is there any benefit to getting a weaker grade bolt for its “stretchiness”? After all, the ability of a bolt to stretch and reform is part of what makes it an effective fastener. In general, no. A properly manufactured high strength bolt maybe be more brittle than its weaker counterpart but the weaker bolt (at least in the case of grade 5 and 8) will both yield AND break before the stronger bolt has begun to yield.

Both grade 5 and grade 8 are available in plain steel and zinc plated steel. The zinc plating for grade 5 is almost always clear and the plating for grade 8 is almost always yellow. They are not functionally different – the color just helps distinguish them from each other. They can also be distinguished by the head markings (three radial lines for grade 5 and six radial dashes for grade 8).