Uses for Rivets in CNC Machining and Manufacturing(deburing Truman)
- source:NEWRGY CNC Machining
One of the key advantages of rivets is that they create a permanent assembly. The riveting process deforms the rivet shank, forming a head on the manufactured end. This joins the rivet tightly to the materials being fastened. Unlike screws or bolts, rivets cannot loosen over time. This makes them ideal for components that need to remain fixed together permanently without failure.
Rivets are commonly used in aircraft construction, for example, to ensure wings and other critical components stay securely fastened over thousands of cycles of stress and vibration. CNC machining allows rivet holes to be added with precision spacing and diameter. The rivets are then installed by automated riveting systems for consistent quality and strength.
High Shear Strength
In addition to preventing loosening, rivets have very high shear strength. This refers to their ability to resist forces trying to slide or separate joined materials sideways. The large head of the rivet withstands these shear forces exceedingly well. This makes rivets a good choice whenever significant lateral stresses will be applied to an assembly.
CNC machined aluminum components destined for aerospace applications, for instance, frequently use rows of rivets instead of welding. The rivets handle shear loads from airflow and flight maneuvers better than welds in thinner aluminum stock. Rivet strength is also less affected by vibration fatigue over time.
No Heat-Affected Zone
The riveting process does not involve heating materials up to melting temperatures, unlike welding. This means there is no heat-affected zone (HAZ) in the surrounding base metal. The HAZ can cause deformation and changes to material properties like hardness and brittleness. Eliminating this with rivets improves both part quality and structural integrity.
CNC machined parts requiring very high precision can benefit from riveted assembly versus welding. The lack of HAZ avoids any unwanted distortion that could compromise tight tolerances and surface finishes. This makes rivets well-suited for precision instruments, medical devices, aerospace components, and similar quality-critical applications.
Ease of Automation
While riveting was traditionally a manual process, CNC automation has made it much simpler and more efficient. CNC machining centers can create the rivet holes, then robotic arms equipped with rivet fastening heads can install hundreds of rivets quickly and consistently.
This automation also enables selective riveting. Specific rivets can be skipped based on dynamic needs. CNC programs can adapt riveting patterns for different material types and thicknesses in mixed-material assemblies. Automated optical inspection can even validate every rivet's installation quality. Overall, CNC improves both the speed and quality control of rivet-based manufacturing.
Rivets come in a wide assortment of materials, head styles, and sizes. This includes standard alloys like aluminum, steel, copper, and stainless steel. Exotic alloys like titanium, nickel, and monel are also readily available. Plastics and other polymer rivets provide lightweight and corrosion resistant fastening.
CNC machined parts made of nearly any material can make effective use of matching rivets. Mixed material assemblies can also take advantage of different rivet materials for optimized performance. The riveting process works for soft plastics or extremely hard materials alike. This material versatility cements rivets as a go-to fastening solution for most assemblies.
No Loose Parts
Rivets contain just a single part - the rivet body. This avoids issues with loose nuts, washers, pins, and retaining clips. Rivet guns or automated riveting systems can rapidly install rivet after rivet without these complications. For applications requiring many fasteners, this simplicity provides real efficiency advantages.
Mass production settings like automotive manufacturing often rely heavily on rivets for this reason. CNC machining allows adding hundreds of rivet holes easily to stampings and sub-assemblies. Rivets then fasten the parts together without loose secondary hardware to slow down or complicate the process.
The smooth uniform appearance of rivet heads often surpasses the visual appeal of bolted connections. Rivets line up neatly in straight rows, providing a clean finished look. The lack of threaded holes also avoids any visible defects or inconsistencies that could ruin high-quality cosmetic appearances.
CNC routed and machined parts intended for visible use routinely take advantage of rivets for enhanced aesthetics. Appliance panels, jewelry, luxury watchcases, furniture, art pieces, and decorative metalwork all benefit from riveting instead of screwing components together. The rivets simplify designs while still providing rugged permanent fastening.
Water and Gas Tightness
Properly installed rivets form completely gas and water tight connections. This makes them ideal for assembling components like pressure vessels that need to contain liquids or gases without any leakage. Rivets avoid the potential porosity problems of welds, which could allow seepage through microscopic holes.
CNC machined parts intended for plumbing systems, chemical plants, fuel tanks, boilers, submarines, and more gain improved sealing when riveted versus welded. Automated riveting also allows efficient leak testing during production - each rivet can be checked individually with pressure testing probes.
Electrical and Thermal Conductivity
Rivets easily conduct electricity and thermal energy from one component to the next. This provides another advantage over adhesive bonding or polymer fasteners. Rivets are commonly used to attach grounding straps, assemble electronics enclosures, and facilitate heat transfer in products requiring heat sinks or dissipation.
CNC machining can add rivets between dissimilar metals like copper and aluminum to create beneficial galvanic corrosion inhibition. The rivets act as sacrificial anodes while also securely fastening the materials. Their conductivity is a key enabler for this corrosion protection approach.
Improved Fatigue Life
Joint fatigue is reduced with properly designed and installed rivets compared to many other fastening methods. The riveting process essentially pre-loads joined materials with compression force. This avoids cyclic fatigue failures caused by vibrations repeatedly stressing fasteners loose and tight.
In dynamic CNC machined products, rivets help prevent premature fatigue cracking around drilled holes. Aircraft, vehicles, railcars, and similar equipment encounter billions of stress cycles over operational lifetimes. Rivets survive these demands better than alternatives while enabling efficient automated assembly.
Blind Fastening Capability
Rivets can be installed in blind holes or other areas with restricted access. Specialty rivet types are designed to flow into confined spaces and then expand for tight fastening. This allows riveting internal components or joining crossed parts that otherwise could not be assembled.
CNC machined enclosures, supports, mufflers, ducting, and various containment vessels apply blind rivets. The automated CNC process creates the rivet holes in the limited access areas. Then automated or manual tooling uses cleverly designed rivets to finish the connections.
Beyond all the performance advantages, rivets also win on cost in most production scenarios. The fast installation of rivets rivals screws and bolts. No secondary operations like tapping threads are required. And expensive consumables like welding wire get eliminated.
CNC machining paired with automated riveting makes rivets highly cost effective for mass production. Fast cycle times, no extra consumables, and minimal quality checking requirements all contribute to the economy of riveting. This cements the process as a production workhorse across nearly all manufacturing industries.
Rivets may appear like simple pieces of hardware, but they enable impressive capabilities that bolts and screws cannot match. CNC machining paired with automated riveting improves quality, durability, and manufacturing efficiency. Rivets will continue seeing wide use thanks to this combination of automated precision and fastening performance. Manufacturers across applications from aircraft to appliances will continue reaping benefits from enhanced riveting capabilities. CNC Milling CNC Machining