Introduction(machinist tools Winfred)
- source:WEINBERG CNC Machining
What are Rivets?
A rivet is a permanent mechanical fastener consisting of a smooth cylindrical shaft with a head on one end. The shaft is inserted into a hole in two or more pieces of material to be joined. The rivet is then deformed on the plain end, forming another head, which clamps the material together. The force created between the two heads is what gives the rivet its holding power.
Rivets have been used since ancient times in construction and manufacturing. Prior to mass production, rivets were hammered by hand. Nowadays, rivets can be installed quickly using modern tools like squeezers and rivet guns. While fasteners like screws and bolts can be removed and reused, rivets form a permanent joint between pieces of material, giving them distinct advantages in certain applications.
Key Uses and Applications
Aircraft and Aerospace
One of the most critical uses of rivets is in aircraft assembly. Rivets are the preferred fastener in fuselage and wing construction. High strength aircraft-grade rivets are made from aluminum alloys and can withstand tremendous stresses in flight. Rows of precision rivets bind layers of aluminum skin and the underlying frame together into a rigid, lightweight unit. Rivets allow for quick installation and can be flush riveted to reduce drag. Their permanent nature prevents loosening due to vibration. Rivets also do not require locking features like bolts.
Bridges and Steel Construction
In steel construction such as bridges, cranes, and buildings, rivets provide a dependable means to assemble beams and girders. Structural steel rivets are heat treated for added strength. The joints withstand shear forces, allowing transfer of loads through connected members. Rivets also accommodate some movement and vibration in steel structures. Riveted connections were very common in iron and early steel bridges and buildings but have been replaced by welds in most modern construction. However, rivets continue to be used in certain applications.
Riveted hulls were once standard in shipbuilding. Steel rivets provided structural integrity to link hull plates to the internal frames. As welding advanced, most shipbuilders transitioned to welded construction. But even today, rivets have advantages in shipbuilding and continue to be used for certain purposes. The rattling of loose rivets can alert ship operators to hull damage. Rivets also provide better vibration damping compared to welds. Ships such as aircraft carriers continue to rely on thousands of rivets in their construction.
Rivets exemplify versatility as they transitioned from industrial uses to clothing applications. Copper rivets reinforce the stress points on denim jeans and jackets where seams meet pockets, button areas, belt loops, etc. Copper's rust resistance and toughness withstand repeated washing and wearing. The first Levi's jeans used copper rivets this way after ordinary thread tore out. It's a fundamental example of rivets increasing durability.
Another decorative use of rivets is in jewelry. Small stainless steel and aluminum rivets act as non-conventional beads or spacers in bracelets, necklaces, and rings. Their boxy, mechanical shape contrasts with round beads. Set into leather or synthetic leather, rivets take on a punk, industrial vibe. Rivet heads can be embossed or engraved with logos and designs for further customization. Rivets work as unique unisex jewelry pieces.
Types of Rivets
Several kinds of rivets suit different applications and materials. Some key types include:
Blind Rivets - Rivets with the flexibility to be set from one side when access to both sides is not possible. The mandrel stems are cut off after installation. Used for sheet metal, plastics etc.
Drive Rivets - Can be driven using hand tools for speed and efficiency in factory settings. Used extensively in aircraft assembly.
Flush Rivets - Have heads that can be driven flush with the surface resulting in a smooth aerodynamic surface. Common on aircraft.
Split Rivets - Designed with serrations so the tail snaps off cleanly at completion leaving half in the hole. Simplify blind side application.
Tubular Rivets - Used for fabrics and in blind applications. The domed head folds outward forming a shop head to clamp materials together.
Screw Rivets - Combined with a female threaded section that a screw fastener can engage. Allow for rapid disassembly if needed.
From early manufacturing to present uses spanning planes, bridges, and clothes, rivets have proven their unmatched versatility as a fastening method. Improved strength, installation, and head styles make rivets adaptable to nearly any environment. While other fasteners may work in certain situations, rivets remain a prime choice for permanent, reliable connections that make the products we use every day possible. Whether purely practical or decorative, they are an integral and often overlooked mechanical component. CNC Milling