Riveting in Sheet Metal Fabrication(aluminum 6061 vs 7075 Jessie)

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Rivets are a crucial fastening technology used extensively in sheet metal fabrication. They create strong and permanent joints between metal components while adding negligible weight. Compared to welding, riveting is quicker and more cost-effective for high volume production. This article will provide an overview of riveting techniques for sheet metal, the advantages rivets offer, and how to select the right rivets for an application.
How Riveting Works
A rivet is essentially a cylindrical shaft with a head on one end. To rivet two or more layers of sheet metal together, holes are drilled or punched through the layers at the joint location. The rivet is inserted into the aligned holes and the tail end is upset, flared out, or bucked against the bottom layer using a riveting hammer or squeezer. This creates a permanent headed connection.
The flaring action compresses the rivet and sheets tightly together while filling the holes. This tension is what gives riveted joints their strength. When properly set, the result is a smooth surface on both sides of the joint. Rivets are available with round, flat, or countersunk heads to suit the application.
Common Riveting Techniques
Hand Riveting
The traditional method uses manual tools to set each rivet individually. Holes are punched or drilled through the materials to be joined. A pneumatic, hydraulic, or hand-powered rivet squeezer upsets the tail to form the second head. Access only from one side is needed, making hand riveting suitable for large assemblies.
Impact Riveting
This technique uses an air-powered hammer with a bucking bar on the opposite side to flare the rivet. Impact riveting is faster than squeezers but requires access to both sides of the assembly. It is ideal for high volume production, such as in the automotive industry.
Self-Piercing Rivets
These specialized rivets do not need a pre-drilled hole. Using a hydraulic or electric setting tool, the rivet pierces through the top layer and flares against the bottom sheet. This joins materials of varying thicknesses and strengths quickly without separate hole punching steps.
Orbital Riveting
This automated process uses a pneumatically powered C-frame press with spinning mandrel and die. Hundreds of rivets can be set per minute in a continuous spiral sequence, making orbital riveting very efficient for large runs. Programmable controls alter mandrel stroke and spin speed for different rivet sizes.
Benefits of Riveting Sheet Metal
Compared to welding, soldering, or adhesives, riveting offers several advantages for assembling sheet metal components:
- Fast processing time and ability to automate for high-volume production
- Only access to one side is needed for many riveting methods
- Minimal heat input so parts undergo less distortion versus welding
- Repeatable quality since fatigue strength is not reliant on skill of welder
- Smoother finished surface without need for grinding or finishing welds
- Allows dissimilar and thin gauge metals to be joined that would be difficult to weld
- Riveted joints can be tuned to desired stiffness by adjusting squeeze force
- Lower cost equipment investment than resistance welding
- Improved corrosion resistance over welds, especially for dissimilar alloys
- Rivets are lightweight and add minimal mass to assemblies
- Vibration resistant connections from clamping force of rivets
Choosing the Right Rivets
With various head styles, materials, and diameters, it is important to select the optimal rivet for an application. Factors to consider include:
- Shear and tensile strength needed
- Materials being joined (aluminum, steel, mixed)
- Grip range or total thickness of all sheets
- Amount of clinch desired to tune joint stiffness
- Static or fatigue loading
- Corrosion resistance requirements
- Weight restrictions
- Cost targets
- Temperature ranges
- Automated or manual setting process
Common rivet materials include aluminum, steel, copper, nickel, and Monel. Aluminum and steel rivets are suitable for most general sheet metal fabrication. Stainless steel provides excellent corrosion resistance. Copper and Monel rivets can withstand higher temperatures.
The diameter, grip length, and head size should be matched to the application requirements and capabilities of the installation tools. Testing riveted coupon samples is recommended to verify joint strength prior to production.
Riveting is a versatile and cost-effective technique for permanently joining sheet metal while adding minimal weight. It offers advantages over welding and other alternatives, especially for mass production environments. With the right rivets selected and proper setting procedures implemented, riveted assemblies can deliver high strength-to-weight ratios and long service life across many industries. Understanding the principles, methods, benefits, and rivet options enables engineers to produce optimized sheet metal designs. CNC Milling