Rivets: An Essential Fastening Solution for CNC(surface finish chart Faithe)
- source:EAGLEBURGER CNC Machining
How Rivets Work
A rivet is an incredibly straightforward yet ingenious fastening component. A basic rivet consists of a smooth cylindrical shaft and a head on one end. The rivet is inserted into pre-drilled holes in two or more layers of material. The plain shank end is then upset, or sm smashed, to form a second head. This creates permanent cylindrical rivet heads on both ends that grip the materials together in a tight, secure joint.
The riveting process induces plastic deformation and cold working of the rivet body. This strengthens the fastener and eliminates loose play in the joint. Rivets form very stiff connections that can withstand vibration, shock loading and cyclic stresses. This makes them ideal for applications like aircraft, bridges, shipbuilding, railcars, trucks and machinery.
CNC machining opens up expanded possibilities for specialty and custom rivet designs and applications. Precision tooled rivet geometries, materials and strengths can be manufactured. CNC also enables selectively placed rivet patterns to maximize joint performance in critical areas.
Key Uses for Rivets in CNC
Rivets serve numerous important functions in CNC fabrication and manufacturing:
- Joining dissimilar metals: Rivets can join metals with different characteristics or properties, such as steel and aluminum. The ductile rivet deforms to absorb differences in thermal expansion.
- Sheet metal fastening: Rivets are highly effective for joining thin sheet metal fabrications. Large riveted assemblies are common in aircraft fuselages, automobile bodies, railcar skins, ship hulls and architectural cladding.
- Machinery fabrication: Rivets are extensively used to assemble machinery frames, attachments,drivetrain and powertrain components, covers and guards. Riveting adds mechanical strength while allowing for disassembly.
- Fixing inserts: Rivets provide solid, precise attachment of threaded inserts, captive nuts and other elements into panels and assemblies.
- Electrical enclosures: Rivets offer reliable fastening of covers, panels and hardware on electrical boxes, control cabinets and housings. Vibration resistance prevents loose hardware.
- Plumbing fixtures: Rivets create durable, watertight joints on sinks, toilet bowls, water heaters, boilers and precision fluid system components.
- Structural frames: Rivets are ideal for connecting structural steel elements like I-beams, channels and plates in buildings, trucks and machinery.
- Securing wear or friction parts: Rivets provide rigid, non-moving attachment of wear or friction plates, bars, bearings and other components subject to movement or vibration.
- Composite bonding: Rivets can join fiberglass, carbon fiber, Kevlar® and other composites to themselves and to metals. The rivets distribute load stresses over a wider area.
- Permanent fastening: Rivets form permanent joints unlike threaded fasteners which can loosen over time. Rivets help prevent loose parts on critical systems.
Rivet Materials and Finishes
Another benefit of rivets is the wide range of available materials and platings:
- Aluminum - Lightweight, general purpose use, some strength
- Steel - Stronger, more heavy duty applications
- Stainless steel - Corrosion resistance, high strength
- Monel - Maximum corrosion resistance
- Copper - Electrical/thermal conductivity
- Brass - Decorative applications
- Titanium - Extreme strength for aerospace use
- Nickel alloys - High temperature resistance
Rivets can also be plated or finished for added performance:
- Zinc - Corrosion protection for steel rivets
- Cadmium - Corrosion protection, sacrificial coating
- Anodized - Harder surface for wear resistance
- PTFE coatings - Lubricity, non-stick
- Colored finishes - Aesthetic customization
CNC-Optimized Rivet Design and Machining
CNC capabilities elevate rivets above being solely commodity hardware. Precision CNC machining allows rivet creation optimized for specific joint requirements:
- Unique diameters, lengths, head styles and shapes
- Stepped walls and multi-diameter shafts
- Custom materials and hardness/strength
- Insert molded composites
- Threaded, pinned or staked shank ends
- Integral precision guides and stops
- Captive washer/grommet configurations
- Blind rivet designs for access from one side
- High-shear punch rivet variants
- Innovative installation tooling
CNC enables on-demand rivet production in smaller batches suited to prototyping, custom machinery and specialty fabrication. Inventory can also be minimized by machining standard rivets at time of assembly.
Easy Installation for CNC Efficiency
Rivets offer efficient installation versus other fasteners:
- Quick punching/upsetting replaces threading or torqueing
- No fixturing or access needed on second side
- Minimal hardware components to acquire
- Installation possible in tight spaces
- Curved surfaces can be riveted
- Fewer specialty tools required
These qualities maximize productivity for CNC shops. Rivet installation is fast, simple and conducive to automation. CNC programmers can utilize rivets to optimize fabrication cycles and minimize handling.
Rivets: An Anchor for CNC Fabrication
From little Cessnas to giant ships, rivets form the fundamental connections that bring manufactured products together. Continued innovation in rivet technology and CNC capabilities will drive future gains in joint integrity, assembly efficiency and manufactured quality across industries. For CNC programmers and machinists, rivets remain highly versatile and accessible solutions for diverse fastening needs and material joining challenges. CNC Milling CNC Machining