What is a Rivet？
A rivet, essentially a permanent mechanical fastener, consists of a head, a cylindrical body, and a tail. These components are made from materials like aluminum, steel, brass, or copper. They join metal sheets or other materials forever.
How Does Rivet Work？
A rivet is characterized by its smooth head and tail, opposite each other on a cylindrical body, resembling a metallic pin. When installed, the preformed head is called the “factory head.” It stays intact, while the tail end deforms to make a “shop head.” The shop head secures the components together. This change happens through a process called upsetting or buckling. In it, the tail is hammered to expand and hold the rivet firmly.
Riveting Techniques and Tools
Riveting can be done by hand with a hammer. Or, for larger projects, with a pneumatic hammer. The manual method involves a significant blow to the rivet, providing enough force to deform the tail and secure the joint. For larger or industrial jobs, pneumatic tools offer more power and efficiency. They streamline the riveting process.
Riveting Process Steps
- Selection: Determine the suitable rivet type, material, and size for your parts.
- Drilling: Drill a hole approximately 1.5 mm larger than the rivet’s diameter.
- Insertion: Insert the rivet into the hole with the tail protruding.
- Deformation: Hammer the tail until it flattens and spreads to about one and a half times its original size, securing the joint.
What are the Different Types of Rivets?
There are many rivet types. They are tailored for specific uses, strengths, and materials in manufacturing. The following are the seven most frequently utilized rivets in sheet metal fabrication projects.
1. Solid Rivets
Often referred to as round rivets, solid rivets are the oldest and most widely utilized form of rivet. They are simple to use and reliable, made typically of copper, steel, or aluminum. Solid rivets have a solid shaft and a head. You can easily deform them with a crimping tool or hammer. The method used depends on the their size and the material’s softness. They are crucial. They assemble thin parts in aircraft, electronics, shipbuilding, machinery, and construction.
2. Blind Rivets (Pop Rivets)
Blind rivets, featuring a head and a mandrel that runs through a tubular body, must be inserted into pre-drilled holes in the materials to be joined. They are expanded by pulling the mandrel through with a riveting tool, effectively securing the materials. Blind rivets are ideal for hard-to-reach areas. You can install them from one side. They are commonly used in aerospace, shipbuilding, and homes.
3. Drive Rivets
Similar to blind rivets, drive rivets have a central mandrel and require no special tool besides a hammer and a backing block to install. They are good for applications where full penetration is unnecessary. For example, for attaching panels or mounting nameplates.
4. Self-Piercing Rivets
Unique for not requiring a pre-drilled hole, self-piercing rivets create their own hole with a chamfered poke. They partially pierce the lower layer of the material while an upsetting die spreads the rivet’s tail to secure the sheets. These are ideal for high-stress applications. They are used to join different materials, like steel and aluminum. These materials are hard to weld.
5. Split Rivets
Split rivets, or bifurcated rivets, are for soft materials like wood, plastic, and leather. This makes them unsuitable for critical uses. They have a split body with sharp tips, enabling them to pierce through the material directly.
6. Tubular Rivets
Tubular rivets have a hollow tube and a head, made from ductile metals that are cold-formed to join. They are common in commercial and electrical applications. This is because they can adapt to many configurations.
7. Flush Rivets
Flush rivets are also known as countersink rivets. They are designed for external surfaces. These surfaces need a smooth finish to reduce aerodynamic drag. They fit into countersunk holes. This makes them great for applications needing a seamless look, such as in aerodynamics.
Additional Rivet Varieties
Other rivet types are also critical in diverse manufacturing contexts:
- Threaded Rivets: These feature an internally threaded mandrel, used extensively in the automotive and aerospace industries.
- Snap-Head Rivets: Known for providing a robust joint, these are typical in construction where high strength is crucial.
- Friction-Lock Rivets: Comprising a stem and sleeve, these are prevalent in aircraft and automotive manufacturing.
- Mushroom Head Rivets: With their distinct low-profile heads, these rivets are excellent for joining materials of varying thicknesses.
- Pan Head Rivets: Their unique cylindrical head design offers exceptional grip and strength, favored in heavy structural construction.
Materials Used For machining Rivets
Aluminum Rivets
Aluminum rivets stand out due to their lightweight and high corrosion resistance. Known for their malleability, these rivets facilitate the creation of complex parts. Aluminum rivets are easy to install. People commonly use them with hand tools. They are the best choice for applications where weather resistance matters.
Stainless Steel Rivets
Stainless steel rivets are well-known for their strength and ability to resist corrosion. They are usually used in tough environments, like aircraft, locomotives, and power plants. Their hardness makes them hard to install with hand tools. So, pneumatic rivet guns are often recommended for these types.
Copper Rivets
Copper is famous for its great ability to conduct electricity and heat. This makes it ideal for electrical appliances. The rivets are also noted for their flexibility. They work well in both application and appearance. This lets them be used in many settings where conductivity is essential.
Steel Rivets
Steel rivets are valued for their fit and clinching ability. This is especially true for those made from low-carbon steel, which is highly flexible. They are used mainly where strong, durable fastening is needed. These rivets need hydraulic or pneumatic equipment for installation due to the material’s toughness.
Brass Rivets
Brass rivets are chosen for their low friction, high strength, and excellent resistance to tarnish. These properties also prevent sparks. This makes brass rivets great for hazardous environments like oil and gas industries. Safety is paramount there.
Advantages of Using Rivets
Simplicity and Installation Efficiency
Rivets are quick and easy to install; a blind rivet, for instance, can be securely set in just a few seconds using a pneumatic tool. This efficiency is helped by the fact that access is only needed to one side of the joint. This greatly streamlines the process. Rivet tools come in three types: air, cordless, and manual. They need little effort and training, making for fast and easy assembly.
Cost-Effectiveness
Using rivets as fasteners is cheap. This is due to their low cost and the efficient production processes involved. These aspects make riveting cheaper than bolted connections. This is especially true when a permanent joint is needed. The affordability of rivets is underscored by their wide-ranging applications across various industries.
Material Compatibility and Diversity
The riveting process offers exceptional versatility in terms of material compatibility. It joins similar and dissimilar materials. These range from metals to non-metals like wood and plastic. It can even join asbestos sheets. This flexibility is key. It’s needed in applications that integrate different materials. They must do so without harming structural integrity.
Strength and Durability
Riveted joints are tough. They have high shear strength and resist fatigue well. This makes them last and stay reliable, especially under dynamic forces. Rivets resist vibration, corrosion, and fatigue. This makes them ideal for tough jobs and harsh environments.
Environmental Friendliness and Aesthetic Quality
Riveting is eco-friendly. It makes no harmful fumes or gases. So, it’s better for eco-sensitive uses. Also, rivets leave a smooth surface after installation. This smoothness adds to a nicer finish than other fasteners like screws or bolts. Those can mar the look of a structure.
Disadvantages of Using Rivets
Permanence and Disassembly
Rivets are made to be permanent fasteners. So, they are unsuitable for structures that need disassembly. This permanence is crucial for permanent installations. These include aircraft body panels and bridges, where disassembly is not expected.
Comparison to Welding
Rivets are sturdy for some uses. But, welding is often a stronger, cheaper, and lighter option. Unlike rivets, which can weaken the base material by requiring holes, welding does not usually reduce the strength of the parts it joins.
Structural and Mechanical Concerns
Riveting can weaken a material’s cross-section. It does this by needing the drilling of holes. These holes may need extra thickness to fix any structural worries. Also, rivet holes can cause stress concentration. This problem is a challenge in some uses.
Cost and Labor Intensiveness
Riveting takes more labor and time than welding. It needs careful layout and drilling. These tasks greatly increase labor costs. This makes riveting more work. This is especially true where time is crucial.
Weight and Noise Issues
Riveted joints are usually heavier than those made by brazing or welding. This is because rivets and strap-plates are heavier. Additionally, the riveting process is noisier. This is mainly due to the hammer blows during the installation.
Leak Issues
Riveting typically does not guarantee a tight, leak-proof joint. Most rivet types, except for hot or self-piercing ones, do not make a watertight seal. This often requires extra effort and costs to make riveted joints watertight.
Applications of Rivet Types
Construction and Joints
Rivets are known for their efficiency in building. They enable the easy connection of parts. These tough fasteners are great for joining wood and metal. They are used in making cabinets, lockers, and shelves. They are key for building strong structures.
Automotive Industry
Rivets assemble vehicle components like chassis and body panels in the automotive sector. Adhesives can join materials with varying properties, like steel and aluminum. They also resist vibration and fatigue well. This shows their importance in making cars.
Aerospace Industry
Aircraft are built with riveting. It’s key because it makes strong, tough, and light connections. Rivets are great for fastening aluminum alloys. Aluminum is crucial for making reliable aircraft parts. These components must resist loosening under vibration.
Jewelry Manufacturing
Riveting is a cold joining method in jewelry production. It lets professionals avoid soldering while making neat and strong connections. This technique uses simple metal forming tools and instructional videos. It is for both expert and amateur jewelry makers.
Sports Equipment Manufacturing
Manufacturers utilize rivets in sports equipment for their high strength and durability. Rivets are used in making items like skateboards, bicycle frames, and ski bindings. Their strength improves the gear’s performance and lifespan.
Home Building and Furniture
In home building, rivets are essential. They are used for tasks such as fastening fiberglass roofing and metal sheets in gutters. They offer a more reliable solution than nails, ensuring the structural integrity of window blinds, doors, and even hanger straps over time.
How to choose the right rivet for your project?
Material Compatibility
Choose rivets that match the strength and environmental needs of your project. Choose aluminum for lighter tasks and steel for more robust ones. Make sure they are compatible to prevent galvanic corrosion.
Joint Requirements
Identify the needed joint type: permanent, semi-permanent, or temporary. Then, select rivets that can handle the associated loads. These loads can be shear, tension, or compression.
Rivet Specifications
Ensure the rivet size and type are suited to the material thickness and project requirements. Choose the appropriate rivet diameter and head type, such as dome or countersunk, to meet both functional and aesthetic needs.
Environmental Factors
Consider the rivet’s operating environment. Choose materials that can resist conditions like corrosion, vibration, and temperature changes. This is needed to keep the rivet durable and functional over time.
