The Importance of Quality Rivets in CNC Machined Parts(different springs Arvin)
- source:ESKRIDGE 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 shaft is inserted into holes in the materials being joined and the head is smashed against the material using tools called rivet guns, deforming the shaft and creating a bulge that holds the rivet in place. The deforming of the shaft is called "bucking" and it cold forms the shaft, upsetting the metal and clamping the materials together.
Rivets come in a variety of styles, sizes, and materials. Some common types include:
- Solid rivets - made of a single material like steel, aluminum, copper, or monel. The most universally used rivet type.
- Blind rivets - rivets that can be installed from one side without access to the back of the material. The mandrel stem is pulled through the rivet body to flare out the end.
- Drive rivets - designed to replace solid rivets. Installed by driving the pre-formed head into the sleeve with a hammer rather than upsetting the end.
- Split rivets - similar to blind rivets but are split down the centerline so they can accommodate various material thicknesses.
Applications of Rivets in CNC Machining
Rivets have become an essential fastening method in CNC machining and manufacturing. Here are some of the most common applications:
- Joining sheet metal components - Rivets are commonly used to join sheet metal parts in aircraft, machines, electronics, and appliances. The riveting process is easy to automate with CNC machining.
- Attaching brackets and housings - Rivets provide a simple and secure way to attach brackets, covers, housings, and handles to larger assemblies. The riveting can be programmed into the CNC machine process.
- Connecting sub-assemblies - Rivets are ideal for connecting modules and sub-assemblies together to form the final product. CNC automated riveting improves efficiency and consistency.
- Permanent fastening - For components that require a permanent joining solution, rivets provide a tight hold and will not loosen over time like bolts. Rivets are vibration and shock resistant.
- Repairs and maintenance - Rivets come in handy for repairs and maintenance work for filling holes left from removed bolts or screws. Riveting can be done on-site without full disassembly.
- High strength-to-weight ratio - Pound for pound, rivets offer very high shear and tensile strength, making them suitable for aircraft and other weight-sensitive applications.
Why Use Quality Rivets in CNC Machining?
With rivets playing such a critical role in CNC machined products, using rivets of the highest quality is essential. Some key benefits of quality rivets include:
- Durability - High quality steel or aluminum rivets withstand wear, pressure, and vibration over years of use without failing. Inferior rivets may crack or break prematurely.
- Reliability - Quality rivets meet exact specifications for shaft diameter, head size, chamfers, and concentricity. This ensures consistent, reliable performance when riveted.
- Material integrity - Top notch rivets maintain material integrity with no voids or impurities that can initiate cracks or corrosion down the road. Verified materials and heat treatment prevent defects.
- Dimensional consistency - Precise dimensional control and consistency of quality rivets allows for accurate automated riveting in CNC programs with no variability.
- Optimized shear/tensile strength - The best rivets are engineered with heads and shank diameters to optimize the rivet’s strength precisely for each application.
- No rework - High quality rivets installed properly will not come loose over time, preventing costly rework and repairs. Avoid problems with inferior fasteners.
- Code compliance - Aerospace, military, automotive, and other industries require rivets that meet very stringent codes and certifications. Top brands comply with these standards.
While quality rivets may cost slightly more upfront, they pay dividends over the lifespan of the CNC machined product through durability, longevity, and performance. The potential rework, repairs, and replacements required with subpar rivets often negate any perceived cost savings from going with a lower priced option. Specifying quality rivets from trusted brands is wise optimization that protects your investment in CNC machined parts.
Selecting the Best Rivets for Your CNC Machined Components
With an understanding of the importance of rivet quality, now let’s examine how to select the optimal rivet style, size, and material for your specific CNC machined parts. Key factors to consider include:
- Materials being joined - Rivet material should match or be compatible with the joined materials to prevent galvanic corrosion. Using stainless steel rivets on aluminum parts, for example.
- Shear and tensile strength needed - Choose rivets strong enough for the stress levels, while avoiding overspecification which adds cost and weight needlessly.
- Hole size - Hole diameters relative to rivet diameters impact strength. Consult engineering specifications.
- Access for tools - Confirm your CNC rivet gun or other installation tools can access the rivets. Specialty tools are available for space-constrained setups.
- Temperature resistance - If riveted parts will experience high temperatures, select rivets designed to withstand those extremes.
- Environmental factors - Specify rivets with coatings or made of materials inherently resistant to chemicals, water exposure, UV light, etc.
- Assembly sequence - Determine best points in the build sequence to rivet sections together based on access requirements.
- Automated vs manual - Look for rivets optimized for automated CNC riveting or manual installation based on your production approach.
- Codes and regulations - Rivets must satisfy all applicable standards for the industry such as AS, MS, NAS, AN, or Mil Spec standards.
Reputable rivet manufacturers have experts available to collaborate with you on selecting optimized rivets for your specific CNC machined products. Don’t leave anything to chance - consult the experts to leverage their knowledge and experience for ideal rivet selection.
In closing, quality rivets are a small but mighty component that deserve careful specification consideration for CNC machined parts and assemblies. Following the guidance provided in this article will steer you towards the best rivets to match your production needs while avoiding problems that can occur down the road from inferior fasteners. Your products will benefit for years to come by investing in high quality rivets for all your CNC riveting needs. CNC Milling CNC Machining