Uses for Rivets in CNC Machining(strength of steel Tom)

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  • source:EAGLEBURGER CNC Machining
Rivets play an important role in many CNC machining applications. A rivet is a mechanical fastener that connects two or more materials by inserting a metal shaft through aligned holes in the parts to be joined and deforming the protruding shaft on one or both sides. Rivets come in a variety of head shapes, materials and installation methods to accommodate different design requirements. Understanding the uses for rivets in CNC can help machinists select the optimal riveting methods for their projects.
Joining Sheet Metal
One of the most common uses of rivets in CNC machining is for joining sheet metal components. Rivets create strong permanent joints while allowing some flexibility in the connection. This is important when working with thin metal sheets that may flex during use. The riveting process involves CNC drilling precisely aligned holes in the metal sheets to be joined, then inserting rivets and using a rivet gun or other tool to flare out the rivet shaft ends. This flaring action clamps the metal layers tightly together. Rivets used for sheet metal include blind rivets, which can be installed from one side, and standard two-sided rivets.
Blind rivets are convenient for CNC applications where access to both sides of the joint is limited. The rivet body is inserted into pre-drilled holes in the metal and a pull mandrel is used to draw the rear end of the rivet shaft back through the body. This flares the rivet head on the accessible side while forming a blind head on the rear surface. Common blind rivet types are pop rivets and break mandrel rivets. CNC programmed riveting with blind rivets allows efficient joining of complex sheet metal assemblies.
Permanent Electrical Connections
In electrical enclosures and junction boxes produced with CNC machining, rivets can provide solid permanent connections between metal conduit fittings, bus bars, mounting plates and housing components. The high clamping force of properly installed rivets forms reliable low-resistance electrical joints that will maintain stability over years of service. Riveted electrical bonds can also guard against loosening of connections due to vibration, thermal cycling and mechanical stress. Proper rivet sizing, material selection, hole sizing and installation method are necessary to achieve optimal electrical performance.
Joining Dissimilar Materials
Rivets allow CNC machined components made of different metals or other materials to be securely fastened together. Differences in thermal expansion, galvanic corrosion potential and mechanical properties between material pairs can make joining by welding or adhesives impractical. Mechanical fastening with rivets avoids these compatibility problems. With proper joint design, rivets can accommodate moderate differential movement between the mating materials as temperature or mechanical loads vary. Rivet materials are chosen to be compatible with the specific materials being joined.
Permanent Attachment of Hardware
Rivets installed with CNC provide a permanent means of attaching hardware such as hinges, latches, handles and feet to enclosures, doors and panels made of plastic, sheet metal or other machinable materials. The high shear and tensile strength of rivet joints keeps attached hardware securely in place without loosening over time. Compared to threaded fasteners, rivets eliminate the possibility of loosening due to vibration or thermal cycling. Rivets also provide a cleaner look compared to exposed screw heads. A wide range of rivet materials, head styles and installation tools allows suitable hardware attachment options for most applications.
Repairing Damaged Threads
CNC machined parts that have damaged, corroded or stripped threaded holes can sometimes be salvaged by drilling out the damaged threads and installing threadless rivets matched to the hole size. This provides a simple permanent repair that avoids the need to replace expensive or hard-to-obtain components. Solid rivet installation fills damaged threads and restores shear and tensile load capacity. For less critical applications, self-tapping thread-rolling screws can be substituted if complete disassembly capability must be maintained. But rivets usually provide the fastest and strongest permanently installed repair.
Key Benefits of Rivets for CNC
Some of the key advantages that make rivets a popular choice for CNC machined components and assemblies include:
- High shear and tensile strength for permanent, vibration-resistant joints
- Allows joining of dissimilar metals and other material combinations
- Wide selection of rivet types and materials to suit specific applications
- Flush heads provide a smooth finished appearance
- Blind rivets permit installation access from only one surface
- Simple fastening method avoids thread galling, cross-threading and corrosion
- Riveting repairs damaged threaded holes quickly and economically
By taking advantage of the unique benefits of rivets, CNC programmers can expand their design options and produce higher quality, more robust parts. With the precision hole alignment and positioning possible with CNC machining, rivets create optimal permanent joints. By selecting suitable rivet types, materials, sizes and installation methods, CNC technicians can implement cost-effective riveting solutions tailored to their specific production requirements. Riveting will continue to play an invaluable role in CNC machined products across countless industries. CNC Milling CNC Machining