Uses for Rivets in CNC Manufacturing(machinable plastic Armand)
- source:GAENOR CNC Machining
High Strength-to-Weight Ratio
A key property of rivets is their high strength-to-weight ratio compared to alternatives. Rivets are made of solid metal and form a permanent mechanical bond. The riveting process work-hardens the shank, increasing its strength. At the same time, rivets add minimal weight versus other fasteners. This characteristic makes rivets ideal for aircraft and other transportation applications where reducing mass is critical. CNC machining is commonly used to drill rivet holes and dimple sheet metal parts during aircraft assembly. Riveting produces lightweight yet strong structures efficiently.
Vibration and Fatigue Resistance
Related to their high strength-to-weight ratio, riveted joints also resist vibration and fatigue well. The positive mechanical interlock between rivet parts provides excellent resistance to loosening under cyclic loads. Riveted truck frames, bridge gussets, rail tracks, and more all leverage this benefit. CNC drilling of rivet holes and robotic rivet placement enable automated, repeatable riveting for large-scale production. Consistent clamping force and hole alignment optimize vibration resistance. Riveting outperforms threaded fasteners in these demanding applications.
Riveted joints form tight, leakproof seals between parts. This makes rivets ideal for pressure vessels, plumbing, HVAC ducting, and similar fluid handling components. The deformation of the rivet shank flares it against the hole sides, sealing the interface. Proper hole sizing and rivet selection prevent gaps that would leak. CNC equipment excel at drilling the many holes for large vessels or ductwork with riveted seams. Automated riveting ensures uniform seals for maximum leak protection.
While plastic screws and bonding adhesives insulate, metal rivets maintain electrical conductivity between parts. This allows rivets to be used in electrical enclosures, motor frames, battery packs, and other conductive assemblies. The direct metal-to-metal contact ensures minimal resistance for grounding and current flow. CNC machining can produce conductive rivets from brass, copper, and other metals to suit different conductivity needs. Riveting joins parts electrically unlike other processes.
No Threads or Curing
Threading fastener holes and waiting for adhesives to cure takes time that riveting avoids. Rivets simply insert into drilled holes and compress through cold forming. This speed makes riveting ideal for high-volume production. CNC automation further reduces process times by drilling many holes rapidly and robotically installing rivets. Riveting machines in assembly lines can install thousands of rivets per hour. The simplicity and speed of the process maximize manufacturing efficiency.
Easy Visual Inspection
The button head of an installed rivet allows easy visual inspection to confirm proper completion. Operators can quickly check for any missing or malformed rivets in a joint. The flush break on the tail end also indicates full compression. This visual verification helps maintain quality standards. Automatic optical inspection systems can further leverage rivet heads for automated assembly inspection after CNC hole drilling and riveting. The visibility of proper rivet installation and compression facilitates process validation.
Once installed, the deformed shank of a rivet mechanically locks it in place permanently. This prevents any vibration loosening that threaded fasteners can suffer. Rivets also cannot loosen from rotation as no torque was applied during assembly. The result is highly secure joints ideal for critical structures. CNC machinery reliably produces consistently clamped, locked joints by automating riveting forces and positioning. Riveting delivers lasting fastening security.
Installation in Limited Space
Rivets only require access to one side of a joint for installation. The riveting tool compresses each rivet by applying force to the head on the accessible side. This one-sided installation facilitates riveting in tight spaces where bolts or screws would be impossible. The riveting process also requires minimal clearance between parts overall. CNC-drilled rivet holes can have tighter edge margins than wide bolt holes. Robot riveting further improves access to cramped assembly spaces.
Corrosion Resistance Options
While steel rivets offer strength, other materials provide excellent corrosion resistance for demanding applications. Stainless steel, aluminum, nickel, and titanium rivets resist rust, oxidation, and other degradation. Monel rivets offer marine and saltwater protection. Exotic alloys can be customized for unique needs. CNC machining allows high-precision production of small rivets from these exotic metals. Specifying the optimal rivet material improves durability in challenging operating environments.
Unlike directly threaded connections, riveted joints have some play and flexibility. This cushioning effect dampens vibration and noise transmission. Appliances, electronics enclosures, office furniture, and more take advantage of this acoustic benefit. Automated riveting provides consistent clamping force to tune the noise isolation as needed. Overall, riveting reduces noise compared to rigid solid fastening methods.
The range of rivet styles and materials allows designers wide latitude when selecting fastening methods. Different rivet head shapes can suit aesthetic needs. Custom lengths and diameters fit unique joint gaps and strengths. Exotic alloys address specialized corrosion protection requirements. CNC machining can produce specialized rivet geometries and alloys on demand to meet application criteria. Rivets offer much more design flexibility than screws or welding.
In summary, rivets are a highly versatile mechanical fastening technology suited to many applications, especially where high strength, vibration resistance, and a sealed permanent joint are needed. CNC drilling machinery and automated riveting systems enable large-scale production leveraging rivets' speed and consistency. When selected and applied appropriately, riveting can produce optimized assemblies efficiently. The unique capabilities of rivets make them a go-to choice for quality manufacturing enterprises. Understanding their advantages and uses drives innovation and improves product performance. CNC Milling CNC Machining