Riveting in Sheet Metal Fabrication(is bronze copper Douglas)

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Rivets are a popular and versatile fastening method used in sheet metal fabrication. They create strong, permanent joints between metal parts. Riveting involves inserting a metal fastener into aligned holes in two or more layers of material. The rivet shank is then deformed on one or both ends to clamp the layers together.
Rivets have been used since ancient times to assemble armor, buildings, ships, bridges and many other structures and products made from metal. Today, riveting remains a key technique in manufacturing and construction. It is commonly used to join sheet metal parts in airplanes, trucks, trains, electronics enclosures, ductwork and numerous industrial applications.
Benefits of Riveting
Riveting offers many benefits that make it a staple process in sheet metal fabrication:
- Strong, permanent joints – Properly installed rivets form tight clinches that do not loosen over time. Riveted joints maintain strength and integrity for the life of the product.
- Vibration resistance – Rivets can withstand high levels of vibration without failing. This makes them well-suited for products like aircraft and vehicles.
- Speed and efficiency – Automated riveting is much faster than welding, screwing or bolting. It takes less than a second to set a rivet. Riveting also requires less preparatory work than welding.
- Material versatility – Rivets work with all common sheet metals, including steel, aluminum, copper, brass and more. Many rivets also join dissimilar metals effectively.
- No heat or sparks – The riveting process produces no heat, sparks or fumes. This benefits safety. It also avoids heat distortion and discoloration, which are common welding defects.
- Visual inspection – Installed rivets have a clear, visible head. Missing or poorly formed rivets can be easily identified through visual inspection.
- Cost-effectiveness – Mechanical fasteners like rivets are inexpensive components. The riveting process has low equipment costs compared to welding or adhesives. This makes it a very cost-effective assembly method.
Types of Rivets for Sheet Metal
Many types of rivets are available to handle varied sheet metal fabrication applications:
- Solid/Round Head Rivets – This classic rivet style has a round head and shank. It is suitable for general applications.
- Countersunk Head Rivets – These rivets have a flat, countersunk head that sits flush with the material surface. This gives a smooth finish.
- Large Flange Rivets – The flange or skirt under the head is oversized to cover large or slotted holes. This allows adjustment during installation.
- Blind Rivets – Blind rivets can be installed from one side when access to the back is limited. The mandrel shaft is pulled to expand the rivet.
- Self-Plugging Rivets – These hollow rivets seal the hole with a “plug” formed from the rivet material during installation. They prevent leaks.
- Structural Rivets – Structural rivets have high shear and tensile strength to withstand heavy loads in critical structures.
- Drive Rivets – Drive rivets have no pre-formed head. The rivet shank is deformed by hammering or driving to form the shop-head.
Choosing the right rivet style is important for achieving a secure joint while avoiding operational issues like leaks, vibration, corrosion and rivet deformation under load. Consulting application guides or manufacturers is recommended when selecting rivets.
Rivet Materials
The most common rivet materials for sheet metal include:
- Aluminum – Lightweight and easy to form. Used for aircraft, appliances and electronics. Prone to galling.
- Steel – Strong, durable and inexpensive. Used in heavy machinery, structures, vehicles and hardware. Can rust.
- Copper and brass – Higher cost but extremely resistant to corrosion. Often used in plumbing applications.
- Monel – Nickel alloy known for corrosion resistance and high strength at extreme temperatures. Common in marine and chemical/petrochemical applications.
- Stainless steel – Provides corrosion resistance and high strength. More expensive but ideal for harsh environments. Common in food processing plants, chemical plants and outdoor applications.
- Titanium – Extremely strong but lightweight. Used in aircraft and high-performance applications despite higher cost.
Thematerial must suit the service environment as well as meet structural requirements. Joint strength relies heavily on proper material pairing between the rivet and sheet metals being joined. Contacting a metallurgical engineer or materials specialist is advisable when uncertain about material chemistry.
Rivet Strength Ratings
Structural rivets are manufactured to standardized shear and tensile strength ratings. Common strength grades include:
- AD43XX – 43,000 PSI minimum tensile strength. 2X,000 PSI minimum shear strength. Low carbon steel.
- AD53XX – 53,000 PSI minimum tensile strength. 3X,000 PSI minimum shear strength. Medium carbon steel.
- AD63XX – 63,000 PSI minimum tensile strength. 4X,000 PSI minimum shear strength. High carbon steel.
- DD17XX – 17,000 PSI minimum tensile strength. 11,000 PSI minimum shear strength. 2117 aluminum alloy.
- NAS1097 – 97,000 PSI minimum tensile strength. 16,000 PSI minimum shear strength. 7075 aluminum alloy.
- NAS1897 – 97,000 PSI minimum tensile strength. 58,000 PSI minimum shear strength. 7178 aluminum alloy.
The “XX” denotes the rivet diameter in 1/16 inch increments. These ratings help engineers select the optimal rivet strength needed for an application. Using rivets with excessive strength adds cost and weight without benefit. Understrength rivets may fail under load.
Rivet Installation Processes
Modern manufacturing applies automated riveting machines to install rivets quickly, consistently and safely. Common processes include:
- Impact Riveting – A piston strikes the rivet head, upsetting the tail to form the shop-head in one hit. Used for blind and some solid rivets.
- Orbital Riveting – Similar to impact but uses an orbital motion to set the rivet. Produces a smooth shop-head finish. Often used for solid rivets.
- Radial Riveting – A wheel rolls over the rivet head to deform the tail precisely and gradually. Allows great control over shop-head shape.
- Rollforming – Combine rolling and upsetting to produce flush rivets with minimal distortion. Used on thin sheet metals.
- Feed Riveting – Rivet feed mechanisms allow high-speed automated installation. Multiple riveting heads act simultaneously for mass production.
- Robotic Riveting – Robots maneuver rivet guns into position for installation in confined spaces. Enables automation of complex assemblies.
- Pneumatic/Hydrostatic – Use pressurized air or fluid to install rivets in inaccessible locations like aircraft wings. No mechanical force required.
For small-scale jobs, manual riveting with hand tools is still common. Operators use rivet guns, squeezers and hammers to deform the rivet. Power tools improve manual productivity and quality for medium-sized jobs. But for large production runs, automated riveting is vastly faster and more consistent.
Riveted Joint Design Principles
Proper design is crucial to achieve optimal riveted joint strength and durability:
- Avoid shear loads – Rivets are weak in shear compared to tension. Lap joints that induce shear on rivets should be avoided when possible.
- Use multiple rows – A single row can distort and elongate the holes under load. Using two or more staggered rows distributes force better.
- Size for grip length – Rivet length should match the total thickness of all sheets being joined to prevent Unsupported rivet tails.
- Allow for eccentricity – Small misalignments during assembly require wider hole offsets and rivet spacing.
- Include washers – Washers help spread load, reduce buckling and prevent pull-through.
- Limit spacing – Compact rivet spacing helps distribute loads over more fasteners.
- Orient perpendicular to load – Rivets should be oriented perpendicular to the applied tension or shear force.
- Select compatible materials – Ensure galvanic compatibility and avoid excessive difference in hardness.
Following established standards, using joint analysis tools, and fatigue testing are also critical for robust long-term riveted joint integrity.
In summary, riveting remains a highly effective, versatile and cost-competitive joining method for sheet metal fabrication. With proper design and process implementation, riveted assemblies offer durable performance across countless essential products and applications. CNC Milling CNC Machining