High Quality Rivets for CNC Machining(extracting a broken tap Mortimer)

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Rivets are a crucial component in many CNC machined parts and products. Choosing the right rivets is essential for creating strong, long-lasting connections in everything from aircraft and automobiles to industrial equipment and consumer products. This article will examine what makes for a quality rivet in CNC applications and provide guidance on selecting the best rivets for your project.
What is a Rivet?
A rivet is a mechanical fastener that consists of two main parts - a smooth cylindrical shaft and a head. Rivets are inserted into holes that are precisely matched to the rivet diameter. The rivet is then deformed on the tail end, spreading it out to form a second head that securely fastens the rivet in place. The resulting connection is rigid and permanent - ideal for CNC machined components that must withstand vibration, shock, and stress.
Key Properties of Quality Rivets
Strength: A quality rivet must be strong enough to handle the forces exerted on the joint over years of use. Aircraft-grade rivets, for example, are exceptionally strong to cope with turbulence and changes in air pressure. Industrial rivets likewise need high shear and tensile strength.
Ductility: Ductile materials like aluminum or steel rivets can deform and flow into the surrounding holes during installation. This creates a tight fit and vibration resistance. Brittle materials are prone to cracking under stress.
Corrosion Resistance: Rivets exposed to weather, saltwater, chemicals, and other corrosive environments must resist oxidation, galvanic corrosion, and other material degradation. Stainless steel and aluminum rivets offer excellent corrosion protection.
Fatigue Resistance: Repeated cyclic stresses from vibration can cause metal fatigue and eventual rivet failure. Quality rivets are less susceptible to work hardening and fracture over time.
Temperature Resistance: In applications with high heat, cold, or extreme temperature fluctuations, rivets must maintain their properties. This may require special alloys or protective platings.
Accuracy: The shaft diameter and head dimensions must conform to tight tolerances, usually +/- 0.002 inches, to match CNC machined hole sizes.
Head Styles: Different rivet head shapes - round, countersunk, modified, etc. - are available for varied applications. Heads snugly fit sockets and surfaces.
Choosing the Best Rivets for CNC Applications
Aluminum Rivets: Aircraft-grade aluminum rivets offer superb corrosion resistance along with high strength-to-weight ratio. Alloy 2117 is a popular choice, as is 7075 for extra hardness and strength. Anodized platings add protection.
Steel Rivets: Carbon steel provides high shear strength and ductility at low cost. It can handle high mechanical stress and vibration. Stainless steel gives the best corrosion protection.
Titanium Rivets: Extremely strong but lightweight titanium rivets meet demanding aerospace applications. The high cost limits use to critical fracture-sensitive areas.
Drive Styles: Blind rivets can be installed from one side when there is only rear access. Self-piercing and flow-drill rivets don't need pre-drilled holes. Special drives set these rivets.
Plating: Zinc, cadmium, and nickel plating resists corrosion. Passivated stainless steel rivets won't gall or seize up during assembly.
Head Styles: Countersunk and modified heads provide aerodynamic smoothness. Dome head rivets maximize bearing stress capacity. Custom head shapes are possible.
Rivet Inserts: Screw threads can be inserted into rivets to accept bolts later. This facilitates field maintenance and repairs.
Rivet Testing: Rigorous testing by rivet manufacturers ensures reliable performance. Common tests include shear/tension pulling, vibration and fatigue, salt spray exposure, and microstructure analysis.
Rivet Certifications: Leading rivet suppliers have their products certified to global standards like NASM, AN, MS, AS, and NSA for proven quality assurance.
Getting the Right Rivets for Your CNC Project
With an understanding of the qualities that make an excellent rivet, you can source the ideal hardware for your specific CNC machining application. Reputable manufacturers will recommend the right rivets and finishes to suit your operating environment and design needs. Small quantity prototyping sets are available for concept testing. By starting your rivet selection process early, you'll help ensure the structural integrity and longevity of your CNC project. Your finished product will function flawlessly for years to come thanks to robust, high-performing rivets. CNC Milling