High Quality Rivets for CNC Machining Applications(chamford edge Chloe)
- source:ZIEG CNC Machining
What are Rivets?
A rivet is a mechanical fastener that consists of two main parts - a smooth cylindrical shaft and a head. The rivet is inserted into a hole drilled through the materials being joined. The tail end of the shaft is upset, either with a hammer or rivet gun. This upsetting deforms the tail and creates a second head, clamping the materials together. Rivets are commonly used in applications where welding is unsuitable or impossible.
Benefits of Rivets
Rivets offer many benefits that make them a popular choice for mechanical fastening:
- High strength and durability. Properly installed rivets form a permanent mechanical connection.
- Vibration resistance. The clamping force of rivets can resist vibration and shock loads better than other fasteners.
- Easy installation. Riveted joints can be installed quickly with basic tools like rivet guns.
- No heat or sparks. Riveting does not require heat or create sparks, making it suitable for flammable/explosive environments.
- Material flexibility. Rivets can join dissimilar or thin materials where welding is unsuitable.
- Corrosion resistance. Many rivet alloys, like aluminum and stainless steel, resist corrosion.
- Light weight. Rivets add very little weight compared to other mechanical fasteners.
- Electrically conductive. Some rivets allow electrical current to flow across a joint.
- Tamper resistance. The upset head makes rivets more tamper resistant than screws or bolts.
Quality Considerations for Rivets
For critical CNC machining applications, rivets must meet stringent quality standards. Some key factors determining rivet quality include:
Material: Aircraft-grade aluminum alloys, titanium, stainless steel, copper, and nickel alloys are common rivet materials. The material must match strength, corrosion, and temperature requirements.
Dimensions: The rivet shaft diameter, head dimensions, and overall length must adhere to tight tolerances, usually +/- 0.002 inches. This ensures consistent fit and performance.
Head shape: Rivet heads are designed in many shapes like round, brazier, countersunk, modified brazier, and more. Applications determine optimal head shape.
Surface finish: Smooth, burr-free finishes prevent galling and ensure consistent clamping force. Common finishes include bare, anodized, and dyed.
Concentricity: The rivet head should be concentric to the shaft to prevent joint distortion. Runout tolerances are typically less than 0.002 inches.
Hardness: Rivets must be properly heat treated to develop sufficient hardness and strength. Hardness typically ranges from Rb70 to Rb95 on the Rockwell B scale.
Straightness: Any deviation from straightness can hinder rivet driving. Straightness tolerances are normally less than 0.015 inches per inch.
Testing: Reputable suppliers use testing methods like salt spray exposure, tensile testing, and microstructural analysis to validate quality.
Rivet Manufacturing Processes
CNC machining enables repeatable production of rivets to precise specifications. Here are some key manufacturing processes:
- CNC heading: Heading machines use CNC tooling to form rivet head profiles. Servo electric presses enable rapid, precision forming.
- CNC thread rolling: Thread rolling forms external threads on the rivet shaft quickly and with greater strength than cutting threads.
- CNC turning: Precision CNC lathes machine rivet shafts to fine tolerances. Programmable tool offsets compensate for tool wear.
- Heat treatment: Ovens with tightly controlled temperature profiles heat treat rivets to develop optimum properties like hardness.
- Plating: Electroplating applies coatings like anodize and dye to rivet surfaces. Plating enhances corrosion and wear resistance.
- Automated inspection: Vision systems, coordinate measuring machines, and other automated inspection tools verify rivet dimensions and surface defects.
- Statistical process control (SPC): Statistical methods monitor production processes to detect any deviations from standards. Early detection prevents quality issues.
By leveraging these CNC capabilities, manufacturers can produce reliable, repeatable rivets tailored to application needs. Precision and consistency are vital for quality-critical industries.
To ensure rivets meet the highest standards, reputable suppliers comply with stringent quality management systems and certifications. These include:
- ISO 9001: Certifies quality management processes that focus on continuous improvement and customer satisfaction.
- AS9100: Aerospace quality management standards even more rigorous than ISO 9001.
- Nadcap: Certifies special processes like heat treating, plating, and non-destructive testing for aerospace.
- ISO/TS 16949: Quality standards for the automotive supply chain. Focuses on defect prevention and risk management.
- ISO 13485: Quality frameworks tailored for medical devices and components.
- ISO 17025: Laboratories must meet this standard for calibrating inspection equipment and testing methods.
- IATF 16949: The highest automotive quality certification, integrating ISO 9001 and TS 16949.
These certifications validate capabilities for producing the highest quality rivets through stringent process controls and quality frameworks.
From aircraft and cars to bridges and medical devices, quality rivets are crucial for product performance and safety. By leveraging precision CNC machining and quality focused manufacturing, suppliers can provide rivets that consistently meet the tightest application requirements. Rigorous quality control standards and certifications further validate these capabilities. For organizations using rivets in critical assemblies, choosing a reputable supplier with these technical and quality capabilities is key to success. CNC Milling CNC Machining