Uses for Rivets in CNC Machining and Manufacturing(hpdc Carol)
- source:ESKRIDGE CNC Machining
Permanent and Semi-Permanent Joining
One of the primary uses of rivets in manufacturing is to join components and parts together. Rivets form a permanent mechanical attachment that is often stronger than other joining methods like screws or bolts. The riveting process deforms the rivet shank, causing it to flare out and clamp materials together. This creates a tight, fixed joint.
Rivets come in varieties like blind rivets and solid rivets for different CNC riveting needs. Blind rivets can be installed from one side for efficient fastening. Solid rivets require access to both sides but offer very rugged connections. Rivet strength comes from both friction and mechanical interlocking as the deformed shank expands.
In some cases, semi-permanent joining is preferred over permanent rivets. To allow for disassembly, special flush rivets can be used that don't flare out and lock materials together. These provide good strength while still allowing non-destructive disassembly later on.
High Strength-to-Weight Ratio
Compared to many other mechanical fasteners, rivets offer a high strength-to-weight ratio. This makes them desirable in weight-sensitive designs, such as for aircraft manufacturing. Rivets are extremely lightweight while still providing substantial shear and tensile strength through the rivet body.
Aluminum and titanium are common rivet materials in aircraft assembly and other lightweight applications. Steel rivets provide the highest shear strength for the most heavy duty connections. Durability, corrosion resistance, and operating environment must also be considered when selecting rivet materials.
Reliable Connections in Vibration/Fatigue Environments
The flared structure of rivets creates joints that resist vibration and shock loads well. The interlocking shank minimizes loosening. Riveted connections are typically rated based on tens of thousands to millions of vibration/shock cycles without failure. This is superior to threaded fasteners in many cases.
For these reasons, rivets are very common in machinery, transportation, and other equipment that sees routine vibration or repeated stress cycles. Properly installed rivets provide reliable, long-lasting connections even under substantial fatigue inducing conditions.
Speed and Automation in Assembly Workflows
Riveting is a fast mechanical joining process, lending itself well to mass production and automation. With the right tools, rivets can be quickly and reliably installed in fractions of seconds. This allows automated riveting cells and rivet fed tooling to achieve very high connection rates.
CNC riveting machines are able to precisely control force, location, and orientation of rivets for accurate joining. Rivet feeding, installation, and detection can all be integrated for optimized cycle times. This automation improves consistency while reducing assembly costs and time.
Riveting is ideal for combining with other automated workflows like CNC drilling/holemaking, robotic transfer of parts, and adhesive/sealant applications. Complete assemblies can be riveted together efficiently with minimal direct human labor required.
Remote Installation in Tight Spaces
Some riveting tools allow access and installation in very tight or obstructed spaces. Right angle rivet setting tools are able to drive rivets at 90 degree angles, simplifying attachment in hard to reach areas. Special small profile tools can insert rivets in confined areas.
This remote capability allows rivets to join complex assemblies that would be impossible or difficult using other mechanical fasteners. Remote accessibility is vital in fields like aircraft manufacturing where internal space is extremely limited. CNC automation enhances this through precision control and positioning.
Improved Appearance from Flush Rivets
For applications where appearance is important, flush rivets provide a smooth, clean look. The minimal protrusion above the surface gives a sleek, streamlined aesthetic. This is useful for automotive, aerospace, architecture, consumer products, and other visually oriented industries.
Countersunk flush rivets can be entirely buried below the outer surface. Other flush varieties like flat head rivets only slightly rise above the joining materials. In all cases, flush rivets provide significant visual improvements over standard round head or protruding rivets.
Flush riveting maintains the structural integrity and benefits of standard rivets while improving aesthetics. It allows for more seamless joining and shaping in design sensitive applications.
Cost Effectiveness and Design Flexibility
Compared to welding, adhesive bonding, or threaded fasteners, riveting offers a cost-effective joining method. Rivets themselves are inexpensive. Installation also requires minimal equipment. This makes riveting economical for prototyping, low volume production, or price conscious manufacturing.
The simplicity of rivets also provides design flexibility. Joint configurations can be easily reconfigured on the fly by changing rivet patterns and locations. No extensive joint redesign is required. This on-demand flexibility is useful for iterating on prototypes and making incremental design improvements.
Riveting also avoids the high setup costs of welding or the long cure times of adhesive bonding. This further improves manufacturing agility, product development speed, and cost efficiency.
Improved Product Durability and Damage Tolerance
Well designed riveted connections improve product durability in multiple ways. First, rivets do not loosen over time which helps prevent damage from vibration. Rivets also maintain joint strength in the presence of minor cracking or fatigue since load is distributed across multiple fasteners.
Additionally, riveted panels can better withstand impacts since force can be absorbed across the entire connection area. Individual rivets can deform and fail locally while the overall joint remains intact. Riveting creates connections with substantial overall damage tolerance.
These factors make riveting a fixture in industries like aerospace and transportation where product lifetime reliability is critical. Riveting maximizes equipment durability even under harsh operating conditions.
Reparability and Field Serviceability
In contrast to permanent joining methods like welding and adhesive bonding, riveted connections allow for convenient field repairs and part replacement. Individual damaged or worn components can be removed and swapped out. This field serviceability is invaluable for maintenance, repair, and overhaul (MRO) activities.
Riveting supports cost-effective reworking of products after deployment. It avoids the need for extensive factory disassembly and remanufacturing. The accessibility provided by rivets simplifies diagnosing and accessing internal faults. This makes riveted products preferred for in-place equipment service applications.
Corrosion Resistance with Specialty Rivets
Standard aluminum and steel rivets have good intrinsic corrosion resistance. Additional protection is available through specialized rivet coatings and platings like zinc, cadmium, anodizing, Alocrom, and others. Stainless steel rivets also provide excellent corrosion resistance.
These specialty corrosion resistant rivets allow riveted joints and connections to withstand harsh conditions like saltwater, chemicals, weather, and other corrosives. They maintain the structural benefits of riveting while adding enhanced environmental durability.
Rivets serve an invaluable role in manufacturing across countless industries and applications. They provide distinct benefits compared to other joining methods through their combination of strength, reliability, cost effectiveness, design flexibility, and durability.
CNC automation expands the capabilities of industrial riveting while improving quality, precision, and efficiency. When appropriately incorporated in manufacturing and design workflows, rivets deliver tremendous utility and value as a go-to mechanical fastener. Their unique advantages will ensure rivets remain a staple technology in fabrication and assembly processes now and well into the future. CNC Milling CNC Machining