Rivets: An Integral Fastener in Manufacturing and Construction(hot runner vs cold runner Evelyn)
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What Are Rivets?
A rivet is a mechanical fastener that connects two or more materials by inserting a metal shaft through aligned holes in the materials and deforming the protruding end to secure it in place. The rivet holds the materials together through friction and compression.
Rivets consist of a smooth cylindrical shaft and a head on one end. To install a rivet, the shaft is inserted into a pre-drilled hole through the materials being joined. The excess length of the shaft extending past the material is called the shank. The shank is then mechanically deformed, usually with a rivet gun or hammer, to create a second head that compresses the materials together. The resulting rivet has a head on each end that sandwiches the materials.
Rivets come in three main types:
- Solid rivets: Made entirely from a single material like steel, copper, or aluminum. Most common type.
- Semi-tubular rivets: Hollow shaft with a solid head. Allows for some flexibility after installation.
- Blind rivets: Have collapsible mandrels that can be inserted through only one side of a material. Used where access is limited.
Once installed, the deformed head puts the rivet shaft in tension while the materials being joined are put in compression. This creates a strong clamping force that provides excellent vibration and fatigue resistance.
Rivet Materials
The most common materials used to make rivets include:
- Aluminum - Lightweight, general purpose use. Easy to install and remove later. Used on aircraft, appliances, electronic equipment.
- Steel - Very strong but heavier. Used in high-stress applications like bridges, shipbuilding, construction equipment. Can be heat treated for added strength. Prone to corrosion if not protected.
- Copper - Excellent corrosion resistance. Primarily used in plumbing applications.
- Monel - Corrosion resistant nickel alloy. Used in marine applications.
- Titanium - Extremely strong but lightweight. Used in aircraft.
The choice of material depends on strength needs, corrosion resistance, weight considerations, and cost. Aluminum and steel cover most general fabrication and construction needs.
How Rivets Work
Rivets create very strong joints by spreading the load across the entire fastener area rather than concentrating it in threads or grooves like other fasteners. Several properties make rivets ideal fastening solutions:
- Riveting tends to cold work and strengthen the materials being joined, increasing the strength of the joint.
- The cold working and compressive forces make an excellent seal against leakage. This is advantageous in pressure vessels and plumbing.
- They have good vibration resistance which prevents loosening over time.
- Installation is quick and requires access only from one side of a joint.
- The joint can flex and move without compromising the fastening integrity.
- Rivets are resistant to shock and fatigue stresses.
- They can accommodate various material thicknesses in one joint.
- Riveted joints fail gradually rather than catastrophically if overloaded.
- Installed rivets are permanent fasteners but can be drilled out if needed.
These qualities make rivets suitable for a wide range of applications from delicate electronics to massive steel bridges.
Uses of Rivets
Airplanes
Rivets revolutionized aircraft construction because of their light weight, strength, and ease of installation. Early canvas-over-wood planes quickly transitioned to all-metal monocoque designs using billions of rivets. Today, nearly all aircraft make extensive use of rivets to join fuselage skin sections, frames, stringers, wings, and other structures. The most common alloys are 2017 and 2024 aluminum along with titanium. Rivets maintain their clamping force at altitude despite large temperature swings and vibration. Aircraft designers select the optimal combination of rivet type, size, material, pitch, and pattern to provide each joint with the necessary shear and tensile strength.
Bridges
Steel rivets are commonly used in the construction of steel bridges. Truss bridges, in particular, require thousands of shop-installed rivets to connect the web members, angles, gusset plates, and other structural elements. Field connections are also riveted for ease of construction. Using hot rivets allows the joints to be tightly sealed against moisture. The reliable clamping force of rivets accommodates vibration, dynamic loads, and fatigue stresses in bridge spans. While high-strength structural bolts have replaced some rivets in modern bridges, rivets are still seen as a tried-and-true fastening method.
Ships
The demand for rivets in shipbuilding increased dramatically in the 19th century as iron and steel replaced wood hull construction. Dozens of riveters would work in teams to follow welders and fasten the steel plates together with pneumatic rivet guns. Rivets performed better than bolts at preventing hull leakage as ships twisted and flexed at sea. Copper and Monel rivets provided corrosion resistance along the waterline and in other wet areas. Battleships consistently used millions of rivets due to their strength, reliability, and ability to withstand explosion impacts. While welding advances have reduced their use, rivets are still applied on ship hulls, decks, bulkheads, masts, and other areas.
Automotive
Rivets play important roles in automobile manufacturing despite the prevalence of welding and adhesives. Body panels use rivets for attachment points and sealing that welding can’t provide. Interior trim pieces, headliners, door panels, seats, and dashboards are commonly joined with blind rivets that provide clamping without unsightly fastener heads. Underhood components rely on rivets for vibration resistance that prevents loosening. Exterior fittings and hardware are riveted for security. While not as extensive as in aircraft, rivets still number in the thousands on automobiles.
Building Construction
The construction industry makes extensive use of blind aluminum and steel rivets for joining studs, braces, ducting, sidings, gutters, roofing, wall panels, and most metal fixtures. Pop rivets allow quick fastening without access behind walls, ceilings, or confined spaces. The vibration resistance prevents loosening which can occur with screws and bolts. Riveted connections also accommodate some differential movement as buildings shift without compromising strength. Weight savings versus welding is also beneficial.
Appliances
Rivets lend themselves well to appliance manufacturing where vibration resistance and air/water sealing are priorities. Housings, doors, handles, hinges, valves, tubing, brackets, and other components are commonly riveted. Using specialty rivets also allows for easy disassembly later for maintenance and part replacement. Given the cost sensitivity of consumer appliances, rivets are an economical fastening solution as well.
Electronics
Electronics enclosures, chassis, brackets, covers, connectors, and wire harnesses frequently employ rivets for permanent fastening and EMI/RFI shielding. The cold working effect of riveting beneficially stresses component mounting points to improve vibration resistance. Weight minimization is also critical in handheld devices. Overall, the reliability, weight savings, and installation ease make rivets ideal fasteners for electronics. Stainless steel and aluminum rivets are common.
While far from a comprehensive list, this covers the primary industries and applications that rely on rivet technology. Innovations in materials, coatings, and installation tools continue advancing rivet capabilities as well. As one of humankind’s oldest and most ubiquitous fasteners, the rivet remains a trusted, proven, adaptable solution across innumerable uses. Their simplicity, performance, and economy cement the rivet’s place in manufacturing for generations to come. CNC Milling CNC Machining