Quality Rivets for CNC Applications(how strong is titanium Audrey)
- source:BREDA CNC Machining
The basic design of a rivet includes a head on one end, a shank, and a second head formed during installation. For CNC applications, rivets with a countersunk head are often preferred as they sit flush with the surface of the material being joined. Countersunk rivets maximize the amount of material contact for the joint. Standard rivet designs have a domed head which protrudes from the surface.
Key dimensions that affect rivet quality and strength include shank diameter, head size, and grip length. Optimal ratios between head size, shank diameter, and grip result in a well-balanced design that resists failure. Rivet manufacturers provide specifications for recommended grip ranges based on shank size. Using a rivet with too short or too long of a grip for a given application can reduce its holding strength.
The strength of the rivet material directly affects the strength of the overall joint. For CNC machinery and fixtures, common rivet materials include various steel alloys, copper, aluminum, and stainless steel. Heat treated carbon steels offer high tensile strength. Stainless steel provides good corrosion resistance when liquid coolants or exposures to moisture are factors.
Aluminum and copper rivets have lower strengths than steel but higher conductivity. This makes them suitable for electronics applications needing to conduct electricity across joints. The intended operating environment is the key factor in selecting proper rivet material strength and corrosion resistance.
The manufacturing process to make quality rivets requires attention to detail. Machine tolerance is critical for keeping rivet dimensions within allowable specs. Heat treating methods are used to achieve the desired material hardness and tensile strength. Deburring techniques are applied to smooth rough edges on the rivet shank.
Quality control checks are implemented at various production stages to verify correct specs. Statistical sampling is done by testing rivet hardness and applying destructive pull tests to measure tensile strength. Advanced inspection methods like microscopy check for potential defects. Proper manufacturing and quality control results in rivets that meet published industrial standards for materials, dimensions, and strength.
CNC Riveting Methods
Installing rivets using CNC equipment improves efficiency and joint quality versus manual riveting. Precision fixturing positions parts so holes align correctly. Automated feeds deliver consistent quality rivets tailored for the particular joint. Programmed machine logic controls the riveting process for optimal results.
Several techniques are available for CNC riveting. Impact riveting uses a hammering action to flare the rivet tail. This expands the rivet to fill the hole and create a flush surface. Orbital forming is similar but uses a spinning action rather than impact. Both methods are fast, simple, and economical.
For higher strength aerospace and critical structural applications, hot riveting is ideal. The rivet shank and surrounding material are heated locally with a rivet gun. As the rivet is inserted into the hot hole, the heating allows the shank to flare smoothly, work-harden, and fill voids. The combination of material expansion and work hardening maximizes joint strength.
For blind joints where only one side is accessible, self-piercing rivets are used. The CNC machinery drills the rivet through the top material and into the bottom layer to form a flush joint. This technique works on dissimilar metals and pre-painted surfaces.
Proper inspection procedures ensure installed rivets meet design specifications. Dimensional checks verify the rivet head size and grip length are within tolerance. The set height, or distance the rivet shank protrudes from the surface, must also meet requirements.
Destructive testing is needed to confirm rivet strength. A sample of rivets is pulled to measure the force required to shear off the shank. The results confirm the rivets meet minimum strength values. Additional quality tests can include tap testing, hammer impacts, and measuring joint gaps under pressure.
For critical applications, advanced inspection methods are used. Ultrasonic testing identifies invisible flaws within the set rivet. Radiographic and x-ray analysis can detect subtle voids or gaps in the joint interface. Quality assurance validation gives confidence the rivet joints will perform reliably under load.
Proper Rivet Selection
Choosing the optimal rivet design, material, and installation method results in maximum joint integrity for CNC machinery and fixtures. Consider factors such as required strength, environmental conditions, precision, vibration resistance, disassembly needs, and processing speed. Leverage the technical expertise of reputable rivet manufacturers to select the proper product specifications and quantities required.
With automated CNC riveting, quality is built into the process when using precision equipment and optimized settings. Validate your riveting program with test samples before full production. This confirms the joints meet target requirements for dimensional tolerances, installed visual standards, and strength testing.
Investing in high quality rivets tailored for your application ensures optimal performance and reliability. The precise automation of CNC riveting maximizes throughput while producing consistent results. With an effective quality assurance program, manufacturers can deliver robust and trusted products to their end customers. Proper rivet selection, automated processes, quality inspections, and testing is the formula for success. CNC Milling CNC Machining