High Quality Rivets for CNC Machines(cad/cam software Vicky)
- source:MAJA CNC Machining
What are Rivets?
A rivet is a cylindrical shaft with a head on one end. The shaft is inserted through pre-drilled holes in the materials being joined. The empty end is then deformed with force, upsetting the rivet and clamping the materials together between the rivet head and the upset end. The rivet shank fills the hole, creating a strong joint.
Common types of rivets include:
- Solid/Blind Rivets - Tubular rivets with a built-in stem. When set, the stem pulls into the rivet, deforming the tail.
- Semi-Tubular Rivets - Hollow rivets that are flush on one side. Requires access to both sides for setting.
- Drive Rivets - Has a pre-formed head. Set by driving the pre-formed head with force to flare out the tail.
- Structural Rivets - Used for high-strength critical joints, usually in steel. Heat-treated for added strength.
For CNC riveting, solid/blind rivets are the most commonly used type.
CNC Riveting Advantages
Installing rivets with CNC machines offers several advantages over manual riveting:
- Speed and Efficiency - CNC machines can rapidly insert hundreds of rivets per hour with automatic tool changing. This is far faster than manual installation.
- Consistency and Precision - CNC positioning ensures rivets are driven straight and at optimal force every time for uniform results.
- Reduced Labor - Automated riveting reduces labor costs associated with manual installation.
- Improved Quality Control - Software controls and SPC data helps identify any quality issues early.
- Flexible Production - CNC programs can be changed to accommodate design changes more easily than manual processes.
Choosing Rivets for CNC
To maximize process efficiency and product quality, care should be taken in selecting the best rivets for your CNC riveting application. Here are key factors to consider:
- Rivet material should match the base material being joined to avoid galvanic corrosion. Common materials include steel, aluminum, copper, stainless steel, and monel.
- The rivet should be strong enough to meet the functional load requirements of the assembly without failing. This includes shear and tensile strength.
Head Style and Grip Range
- Rivet head style impacts tooling/feeding. Grip range is the minimum-maximum material thickness the rivet can clamp. Select rivets that match your application.
- Quality rivets have properly formed heads, smooth shafts, and consistent hardness/ductility to set reliably without cracking or breaking. Verify supplier quality control.
- Diameter variation directly affects hole fill. Tighter tolerances improve consistency and joint quality for CNC setups.
- Consider rivet feedability for your CNC machine. Vibratory bowls, tape feeds, and auto feeds are common options.
By taking these factors into account when sourcing your rivets, you can avoid many potential problems in your CNC riveting process, improving quality and productivity.
Manufacturing Quality Rivets
For manufacturers producing their own rivets, strict process controls are needed to achieve rivets suited for precision CNC installation. Here is an overview of critical steps in manufacturing quality rivets:
Raw Material Selection
- Start with rod/wire stock with the proper diameter, hardness, and composition for the rivet material. Inspect chemistry and physical properties.
Forming the Rivet Head
- Heading applies force to flare out one end of the rivet into the head shape. Maintaining process control is key to proper material flow and head geometry.
- For some materials, heat treatment helps enhance rivet strength. Processes like quenching and tempering require precise temperature and time controls.
- Any residual curvature from preceding operations must be corrected to achieve straight, cylindrical rivets. Multiple straightening rolls/dies can improve straightness.
- Barrel tumbling or other surface finishing methods help smooth surface defects and obtain a uniform finish. This aids rivet feeding and installation.
- 100% inspection of dimensional tolerances, surface defects, hardness, and other factors ensures only rivets within spec are released for CNC use.
By mastering these production steps and implementing robust quality systems, manufacturers can supply exceptionally consistent and reliable rivets optimized for automated CNC riveting.
In summary, quality rivets are a must for trouble-free, high-precision CNC riveting. Careful attention should be given to material selection, physical properties, dimensional accuracy, surface finish, and overall defects when sourcing or producing rivets for CNC machines. This ensures smooth automated feeding and reliable, consistent rivet setting in your production line. With robust process controls and the right rivets, manufacturers can reap the full benefits of automated CNC riveting for faster, higher quality manufacturing. CNC Milling CNC Machining