Types of Rivets: A Comprehensive Guide
Rivets are among the most traditional fasteners used in mechanical applications, distinguished by their toughness and durability.
With a wide variety tailored to specific needs, this article provides a comprehensive guide on rivet types, their working processes, and numerous applications.
Additionally, we compare riveting and welding to help you determine the best option for your project.
1. What is a Rivet?
A rivet is a permanent mechanical fastener used to join two or more pieces of material together.
It consists of a cylindrical shaft with a head at one end. The other end is inserted into a drilled or punched hole, and then deformed or spread so that it becomes wider than the hole, preventing it from falling out.
Rivets are commonly used in applications where high strength and reliability are necessary, such as in aerospace, shipbuilding, and automotive industries.
2. How Does Rivet Work?
A rivet is a permanent mechanical fastener whose basic structure consists of a head and a tail. When installed, the rivet is placed in a punched or drilled hole and then fixed in place by upsetting or bending (i.e. deforming) the tail so that it expands to about 1.5 times the original shaft diameter.
This process creates a new “head” at the other end by crushing the “tail” through impact, forming a new product that is roughly dumbbell-shaped.
A Stepwise Guide to the Riveting Process
- Material Preparation:
- Ensure the materials to be joined are properly aligned.
- Mark and drill holes for the rivets, making sure the holes are slightly larger than the rivet shaft for easy insertion.
- Rivet Selection:
- Choose the appropriate type of rivet based on material thickness, application, and strength requirements. Consider factors like material, size, and type (solid, blind, etc.).
- Inserting the Rivet:
- Insert the rivet through the pre-drilled hole so that the head rests on the surface of the material.
- For blind rivets, insert the mandrel into the rivet gun.
- Setting the Rivet:
- For solid rivets: Use a rivet hammer or pneumatic rivet gun to compress the rivet tail, forming a second head on the opposite side to lock the rivet in place.
- For blind rivets: Use a rivet gun to pull the mandrel, causing the rivet body to expand and secure the materials. The mandrel will break off when the rivet is fully set.
- Finishing:
- Solid Rivets: Ensure the rivet tail is fully compressed and properly formed into a dome or flat shape, depending on the application.
- Blind Rivets: Check that the rivet is securely fastened and that the mandrel has snapped off cleanly.
- Inspection:
- Verify that the rivet is properly set, with no gaps or looseness between the materials.
- Ensure the rivet head and tail are flush with the surface, ensuring a secure and neat finish.
- Surface Treatment (Optional):
- Depending on the application, apply a surface treatment such as painting, plating, or coating to protect the rivet and materials from corrosion and wear.
By following these steps, you can achieve a strong and durable riveted joint, suitable for a wide range of applications.
3. Types of Rivets Used in Manufacturing
Solid Rivets
Solid rivets, also known as round rivets, are renowned for their simplicity and reliability.
They consist of a solid shaft with a head, typically made from copper, steel, or aluminum. Deformation of the tail using a hammer or crimping tool secures the materials together.
Commonly found in aerospace, shipbuilding, machinery, and construction, these rivets are valued for their strength and durability.
Blind Rivets (Pop Rivets)
Blind rivets are designed for single-sided access, consisting of a hollow body and a mandrel. Installation involves pulling the mandrel through the body, causing it to expand and form a secure bond.
These rivets are popular in electronics, appliances, and automotive industries for their speed and convenience.
Types include pull-core, threaded, and drive pin rivets.
Tubular Rivets
Tubular rivets have a hollow shaft, making them easier to deform and install than solid rivets. They are ideal for lightweight applications such as leather goods, clothing, and small appliances.
Common types include compression tubular, full-tubular, and semi-tubular rivets.
Split Rivets
Split rivets have a shaft that divides into two legs. When inserted, the legs spread apart, creating a firm grip in softer materials like wood, plastic, or leather.
These rivets are suitable for low-strength applications and are often used in furniture or crafts.
Flush Rivets (Countersunk Rivets)
Flush rivets are designed to sit flush with the joined surfaces, making them ideal for applications requiring smooth surfaces, such as in aircraft and automobiles.
They are commonly used where aerodynamics and aesthetics are critical.
Drive Rivets
Drive rivets have a smooth shaft and a central drive pin. The pin is driven into the body, causing the shaft to expand and lock the rivet in place.
These rivets are suitable for light-duty applications like signage or insulation panels.
Self-Piercing Rivets
Self-piercing rivets are designed to penetrate materials during installation without needing pre-drilled holes.
They are commonly used in the automotive industry and sheet metal fabrication for creating strong joints without damaging the material.
Friction Lock Rivets
Friction lock rivets function similarly to expansion bolts. If there is sufficient strain, the shaft breaks just below the surface.
These rivets are used in the aerospace industry for maintaining and repairing light aircraft.
Explosive Rivets
Explosive rivets contain a small explosive charge that activates upon heating, causing the rivet to expand and secure the joint.
These rivets are used in specialized applications like aircraft and military equipment, where access to both sides of the joint is limited.
Detailed Components of Rivets
- Rivet Head: The part of the rivet that remains visible after installation. It can come in various shapes such as round, flat, or countersunk, depending on the application.
- Rivet Body (Shank): The cylindrical part of the rivet that passes through the materials being fastened. It is either solid or hollow, depending on the type of rivet.
- Mandrel (for Blind Rivets): A central rod inside blind rivets that helps expand the rivet during installation. After the rivet is set, the mandrel breaks off, leaving the rivet in place.
- Drive Pin (for Drive Rivets): A small pin inside drive rivets that, when driven into the rivet body, forces the body to expand and hold the materials together.
Each rivet type is selected based on specific application needs, including material compatibility, strength requirements, and installation conditions.
Rivets provide a reliable, permanent solution for joining materials across various industries.
4. Materials Used for Rivets
Aluminum Alloy
Aluminum alloy is commonly used for rivets due to its good corrosion resistance and suitability for harsh climates. It is ideal for lightweight applications in aviation, automobiles, and electronics.
For instance, 2117 aluminum alloy rivets are extensively used in aircraft structures for their corrosion resistance and no need for heat treatment.
Copper
Copper rivets utilize their deformation or interference fit to connect parts. They offer oxidation resistance and perform well in various applications.
Copper-nickel alloy rivets, composed of copper, nickel, iron, and magnesium, enhance strength and provide anti-rust and anti-compression properties, performing excellently in high-temperature environments, particularly in shipbuilding.
Iron
Iron is commonly used for rivets in cost-sensitive applications. Though iron rivets are softer, prone to oxidation, and less effective post-electroplating, they remain a viable option due to their affordability.
Tungsten Alloy
Tungsten alloy is used for rivet mandrels, providing maximum density and durability. The mandrels are ground and polished to facilitate use and prevent damage during clamping.
Zinc Alloy
Zinc alloy rivets are cost-effective with better plasticity than iron. They yield good electroplating results but can be brittle and prone to oxidation and rust.
Stainless Steel
Stainless steel, an alloy of iron, nickel, and chromium, is prized for its corrosion resistance due to a protective surface layer. It offers high strength and durability, making it ideal for rust-resistant applications.
Titanium Alloy
Titanium alloy rivets are biocompatible and used in medical implants due to their ability to minimize bodily rejection. They are known for their shape memory, restoring to their original form at specific temperatures.
Special Steel Wire
Special steel wire is used for rivets due to its excellent mechanical properties and corrosion resistance. It undergoes processes like forging, hardening, and tempering to ensure strength and durability in various environments.
5. Applications of Rivets
Rivets are versatile fasteners utilized across various industries due to their strength, durability, and reliability. Here are some common applications:
Aerospace Industry
Rivets are essential in assembling aircraft structures like fuselages, wings, and tail sections. Solid rivets are favored for their high strength and ability to withstand extreme stresses and vibrations. Flush rivets ensure a smooth, aerodynamic surface.
Automotive Industry
In the automotive sector, rivets join metal and composite materials in car bodies and panels. Blind rivets are ideal for areas with single-sided access, such as door panels or chassis assembly.
Construction Industry
Rivets are critical in steel structures, bridges, and high-rise buildings, offering strong and reliable connections. Structural steel and solid rivets are used to join large metal plates in beams and frameworks, ensuring long-term stability.
Shipbuilding
In marine applications, rivets assemble hulls and structural parts of ships and boats. Copper and stainless steel rivets are preferred for their corrosion resistance in marine environments.
Electronics Industry
Rivets secure components within electronic devices, such as circuit boards and housing cases. Small blind rivets and drive rivets are favored for their ease of installation and secure hold on delicate parts.
Furniture and Appliances
In furniture and appliances, rivets serve both functional and aesthetic roles. Tubular rivets are common in furniture assembly, while pop rivets facilitate quick assembly in home appliances.
Railways
Rivets are used in constructing and maintaining railway tracks, train carriages, and structural components. Their resistance to vibration and shear forces makes them a reliable choice for applications subject to frequent movement.
Military and Defense
Military vehicles, armored vehicles, and aircraft rely on rivets for secure and durable connections that withstand high stress and extreme conditions. Explosive rivets are often used for assembling parts in combat aircraft and defense equipment.
Home Improvement and DIY
Blind rivets are popular for DIY projects and home improvement tasks, providing easy and quick solutions for securing metal, wood, and plastic materials in non-structural connections.
Medical Devices
In the medical field, stainless steel and titanium rivets are used in surgical instruments, implants, and other medical equipment due to their biocompatibility and corrosion resistance.
Rivets are indispensable in various industries, ensuring strong, durable, and efficient fastening solutions in applications that require high reliability and performance.
6. Riveting vs. Welding: Which One Should You Choose?
When deciding between riveting and welding for joining materials, it’s important to consider the advantages and drawbacks of each process based on your specific application needs.
Riveting
- Advantages:
- No Heat Required: Riveting is a cold process, making it suitable for materials sensitive to heat or deformation.
- Easy Inspection and Maintenance: Riveted joints are easily inspected for failure and can be disassembled for repair or replacement.
- Strong, Lightweight Connections: Rivets are ideal for lightweight structures where the connection strength is crucial but excess heat from welding could damage the material.
- Corrosion Resistance: Rivets made of non-corrosive materials (e.g., aluminum, stainless steel) can resist harsh environments.
- Disadvantages:
- Time-Consuming: Riveting requires drilling holes and manually setting each rivet, making it slower than welding.
- Weaker in Shear: Riveted joints are generally weaker in shear compared to welded joints, so they may not be suitable for heavy-load applications.
- Best for:
- Aerospace, marine, and construction industries, where lightweight and strong joints are needed, and materials can’t be exposed to heat.
- Applications requiring frequent disassembly or maintenance, such as furniture and electronic assemblies.
Welding
- Advantages:
- Stronger Bonds: Welding creates a continuous bond between materials, providing superior strength, especially in heavy-duty applications.
- No Need for Holes: Welding doesn’t require holes, preserving the material’s integrity and eliminating the risk of weakening the structure.
- Faster Process: Welding can often be completed more quickly than riveting, especially for large structures.
- Disadvantages:
- Requires Heat: Welding involves high heat, which can distort or weaken heat-sensitive materials like aluminum or thin metals.
- Permanent Joints: Welded joints are difficult to disassemble without cutting or damaging the materials.
- Inspection and Maintenance: Welds can be harder to inspect for internal defects, and welded joints may require regular maintenance, especially in corrosive environments.
- Best for:
- Heavy-duty applications like automotive, machinery, and structural steelwork, where strength is the priority.
- Permanent structures where disassembly is not required and the materials can withstand heat.
Which to Choose?
- Choose Riveting: If you need lightweight, easily maintainable, or heat-sensitive joints, especially in aerospace, electronics, or marine industries.
- Choose Welding: If your project requires maximum strength and durability, and heat is not a concern, especially in automotive, machinery, or structural work.
Ultimately, the choice between riveting and welding depends on your project’s strength, material, maintenance, and assembly requirements.
7. Conclusion
Rivets are the ideal alternative to bolts, nuts, screws, and welding. They are more dependable and long-lasting fastening materials than several other connectors.
In summary, rivets are a crucial element in modern engineering and manufacturing. Their ability to provide durable, reliable connections across a wide range of applications highlights their importance in maintaining structural integrity and performance in various industries.
Whether for industrial use or everyday applications, rivets continue to be a vital component in achieving secure and effective assemblies.
However, choosing the ideal material for your rivets is advisable as you select the rivet type that suits your projects best. If you have any questions about rivets, you can contact us at any time.
8. FAQs
Q: What is the difference between tubular and split rivets?
A: Tubular rivets have a hollow core and are often used in lightweight applications such as leather goods or clothing. Split rivets, on the other hand, have a tail that splits into two or more prongs and are used for fastening softer materials like wood or plastic.
Q: How are rivets installed?
A: Rivets are typically installed using tools such as hammers, rivet guns, or automated machines. The installation process involves placing the rivet in a pre-drilled hole and deforming the tail end to create a secure connection. The method of installation varies depending on the type of rivet and the application.
Q: What are the advantages of using rivets over other fastening methods?
A: Rivets provide a strong, permanent connection that can withstand vibrations and shear forces. They are cost-effective, easy to install, and require minimal maintenance. Rivets are also versatile and can be used in a wide range of materials and applications.
Q: Can rivets be used for high-temperature applications?
A: Yes, rivets can be used in high-temperature applications, but it is important to select the appropriate material. Stainless steel and titanium rivets are often chosen for their ability to withstand high temperatures and maintain their integrity under stress.
Q: How do I choose the right rivet for my application?
A: To choose the right rivet, consider factors such as the material being joined, accessibility, strength requirements, and environmental conditions. The type, size, and material of the rivet should be selected based on these factors to ensure a secure and effective connection.
