Finding Quality Rivets for CNC Machines(custom die casting Ruth)
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- source:BREDA CNC Machining
Rivet Material
The material used to make rivets directly impacts their strength, corrosion resistance, temperature range and suitability for different joining applications. Common rivet materials include:
- Aluminum - Lightweight, corrosion resistant, high strength-to-weight ratio. Used for aircraft, marine applications. Not suitable for high temperature environments.
- Steel - Strong, durable for high load applications. Prone to corrosion unless properly coated. Different alloys offer high strength or corrosion resistance.
- Stainless Steel - Excellent corrosion resistance. Provides high strength and temperature resistance. More expensive than other steel rivets.
- Copper - High temperature resistance, electrical/thermal conductivity. Lower strength than steel or aluminum. Used for boilers, electrical applications.
- Monel - Corrosion resistant nickel alloy. Retains strength at high temps. Used for marine, chemical/petroleum applications.
- Titanium - Extremely strong and lightweight. Resists high temps and corrosion. Costly but valued for aerospace applications.
For CNC riveting, aluminum and steel rivets are common choices. Pick a material suited for the service environment and strength needs of the application.
Rivet Dimensions
The diameter, head height, shank length, and other dimensional attributes of rivets affect how they fit into drilled holes and deform to create a solid joint. CNC programs rely on precision rivet dimensions to achieve accurate positioning and clinching.
Key dimensions include:
- Diameter - Matches hole size drilled into workpieces. Common sizes from 1/16” to 3/8”.
- Head Height - Clearance needed between rivet head and workpiece surface. ~1.5x diameter.
- Shank Length - Grips workpieces of specified total thickness when riveted. Allows clinch at tip.
- Grip Length - Portion that clamps workpieces. Slightly less than shank length.
- Tail Length - Excess portion cut off or flattened after riveting to form shop head.
Rivets must have straight, concentric dimensions within tight tolerances for CNC consistency. Reputable manufacturers will provide certifications. Random sampling and micrometer measurements also help verify critical dimensions.
Rivet Head Styles
Different rivet head styles are available to suit various applications and installation methods:
- Countersunk - Flat head for flush fit into countersunk holes. Aerodynamic profile.
- Universal - Rounded head good for clinch joints. Most common for structural applications.
- Flat Head - Low profile head for smooth exposed surface appearance.
- Pan Head - Shallow rounded head with small standoff. Decorative appearance.
- Truss Head - Low dome head. Wider bearing surface to spread forces.
- Large Flange - Wide domed head. Highest bearing surface area. Often used in composite materials.
For CNC riveting, universal and flat head rivets are common choices. Pick heads that provide sufficient material to flare out and grip parts without excess to interfere in tight spaces.
Rivet Hardness
The hardness of the rivet metal determines the strength and deformation ability during installation. Annealed soft rivets are easier to buck and flare under pressure. Hardened rivets resist deformation and stay tightly clinched.
- Soft rivets - More malleable, easier to flange with hand tools. Prone to loosening over time.
- 1/4 hard rivets - Moderate increase in strength over soft. Balance clinchability and resistance to vibration loosening.
- 3/4 hard rivets - Significantly higher strength and clinch grip. Used in high stress applications. Require higher riveting force.
- Full hard rivets - Maximum strength and clinch retention. Can be brittle if overstressed. Require heavy duty installation tools.
For CNC riveters, medium hardness levels like 1/4 hard provide a good blend of clinching ability and joint integrity. Softer rivets lack holding power while harder ones cause excessive tool wear.
Rivet Certifications
Reputable rivet manufacturers will have their products certified to meet various industrial specifications that validate their quality and consistency. Common standards include:
- ASME - American Society of Mechanical Engineers standards for dimensions, mechanical properties, testing methods.
- ASTM - American Society for Testing and Materials standards focused on material chemistry, quality, test procedures.
- MS - Military Standards with specifications used across aviation, aerospace, defense applications.
- AN - Air Force-Navy standards containing requirements used by the armed services.
- NAS - National Aerospace Standards centralized system of aerospace rivet specifications.
- ISO - International Organization for Standardization sets globally recognized industrial and commercial standards.
Look for rivets certified to applicable standards for your industry and application needs. The compliance provides assurance they have passed rigorous quality control testing.
Sourcing Quality Rivets for CNC
When procuring rivets for your CNC riveting operations, go through reputable distributors that specialize in fasteners and hardware components. Building relationships with sales engineers allows tapping into their expertise. They can recommend the best rivet options and provide certifications for the products they supply.
Leading rivet manufacturers like Alcoa Fastening Systems, Atlin, Cherry Aerospace, and L.A. Fasteners have longstanding reputations for supplying quality rivets that adhere to tight tolerances and standards. Their distributors can quickly fulfill orders for a broad range of rivet materials, diameters, head styles, and specifications tailored to your CNC machine setup and assembly requirements.
Implementing a thorough quality assurance process is prudent for verifying rivets before using them for production jobs. Performing checks of the rivet diameter, head dimensions, hardness, clinchability, pull strength, and other key performance metrics on sample rivets provides a final validation of their suitability. Catching any defects or nonconformities prevents headaches down the line.
Properly equipping a CNC machine with quality rivets helps maximize efficiency and throughput for riveting operations. The right rivets allow taking full advantage of programmed automation while giving confidence in creating durable, lasting joints. With an attentive focus on rivet selection and quality verification, manufacturers can achieve consistent, high-quality riveted assemblies with CNC automation. CNC Milling CNC Machining