Uses for Rivets in CNC Machining and Manufacturing(heat treatment of metals Gale)
- source:YESCOM CNC Machining
Aircraft and Aerospace Applications
One of the most common uses of rivets is in aircraft and aerospace manufacturing. Rivets are relied upon to hold together the thin aluminum skins that form the exterior surface of airplanes. Rows of rivets join the various sheets and structural components on aircraft wings, fuselages, and other parts. The integrity of these riveted joints is crucial for passenger safety.
Rivets are often used in aircraft assembly along with specialized fasteners like hi-lok pins and hi-tigue pins. The FAA has strict standards and testing procedures to ensure rivets meet shear strength and vibration resistance requirements. Aircraft-grade rivets are typically made from aluminum, titanium, or specialty alloys.
CNC machining is used to drill consistent, precise holes for rivets to be driven into. CNC also aids in fabricating the rivets themselves to aerospace-level standards. Using CNC helps improve quality control and reduce errors in rivet placement and installation compared to manual methods.
Metal Building and Bridge Construction
Beyond aircraft, rivets are also ubiquitous in the construction of metal buildings, bridges, towers, and other structures. Steel I-beams, girders, and structural columns are joined together using high-strength rivets. CNC drilling ensures rivet holes line up exactly between adjacent structural members. Consistent hole diameter and rivet installation is key to avoiding failures.
Architects and engineers rely on computer stress analysis to determine the ideal rivet size, spacing, and arrangement to withstand shear, tension, compression, and vibration forces. CNC fabrication of custom structural rivets to meet application demands is common. Specialty rivets like blind rivets and tubular rivets allow installation where only one side is accessible.
CNC Punching and Cutting
CNC punch presses and cutting machines are commonly used to mass produce rivet components from sheet metal. Punching can create the rivet head and shank in one stroke with minimal material waste. Cutting machines can also precisely slice rivet blanks from sheet stock.
Using CNC for punching and cutting provides consistency in rivet dimensions and quality at high volumes. The automation increases throughput and reduces labor costs compared to manual fabrication methods. Different rivet sizes, material types, and head shapes can be accommodated by changing the CNC tooling.
Secondary CNC processes like deburring, washing, heat treating, and plating may be utilized after initial punching or cutting depending on the rivet specifications. CNC allows efficient transfer between these finishing steps.
Precision Machined Rivets
While punching works for basic rivets, precision CNC machining can produce specialized designs. On a CNC lathe or screw machine, the rivet shank can incorporate unique locking features like splines, lobes, grooves, or threads. These mechanically interlock with the receiving hole to prevent spinout.
CNC milling provides even more flexibility for complex geometric rivet shanks and heads. Keying features can be added to integrate with installation tools. Precisely machined rivet components minimize play and improve joint stability compared to plain round shank rivets.
Exotic alloys including titanium, Inconel, and corrosion-resistant platings can be accommodated with CNC machining. Thread rolling and other secondary processes can also be automated. This facilitates small batch production of high-value rivets.
Installing Rivets with CNC
In addition to fabricating rivets, CNC automation assists with installing them to assemble products. CNC drilling machines can rapidly create hundreds of accurately aligned rivet holes. Combined with computer-controlled riveting guns, entire sections can be riveted together without manual intervention.
For large aircraft wings, specialty CNC-guided robots can crawl along the structure to drive rivets. This prevents fatigue and injury issues associated with human riveters constantly working overhead in tight spaces. Automated systems also allow selective riveting so only every nth rivet is installed first. This reduces distortion before the final rivets are set.
CNC riveting technology boosts construction speed of high-volume metal products like HVAC ducting. Operators simply position the materials under the CNC machine and initiate the automatic riveting program. The CNC system handles all hole drilling and rivet installation. Riveting automation will likely expand into more areas as the capabilities of CNC machines and robots continue improving.
Inspecting Riveted Joints
CNC enables automated inspection of riveted assemblies. Laser profilometers can scan surfaces to check for protruding or uneven rivet heads. other optical systems can look for cracks radiating from rivet holes. Vibration analysis detects loose rivets based on characteristic frequencies.
This rapid automated inspection after riveting reduces escape of defects. Problems can be identified and reworked in real-time rather than later down the production line. Dense and consistent data helps continuously refine riveting processes.
Maintenance and Repair Applications
Aircraft mechanics frequently use specialty CNC tools to drill out and replace worn or damaged rivets. Hand drilling is prone to wandering that enlarges holes and weakens joints. CNC provides precision guidance while controlling depth to avoid drilling through exterior surfaces. This minimizes repair work needed.
CNC milling can also cut away deformed rivet heads prior to re-riveting. Damaged surrounding material can be patched and re-drilled. CNC allows doing rivet repairs right the first time in tight spaces. This reduces aircraft downtime and disassembly requirements.
Riveting remains an essential fastening technique across manufacturing. From aircraft assembly to bridge construction, rivets offer unique benefits other fasteners cannot provide. CNC machines and automation continue increasing riveting precision and efficiency across many applications. Ongoing advances will expand the possibilities for utilizing rivets in design and manufacturing. CNC Milling CNC Machining