High Quality Rivets Are Essential for CNC Machining(injection molding defects Victor)
- source:ESKRIDGE CNC Machining
What Are Rivets?
A rivet is a two-part mechanical fastener that consists of a smooth cylindrical shaft and a head. The shaft is inserted into pre-drilled holes in two or more layers of material that are to be joined. The rivet is then deformed mechanically using a riveting tool which compresses and flares out the tail end of the rivet. This creates a second head that locks everything together.
The flaring process work-hardens the rivet material and upsets the surrounding materials, creating a very tight fit. This assembly cannot move laterally or be pulled apart. Rivets are commonly used to assemble aircraft, bridges, ships, railroads, and many other products where permanent mechanical joints are needed.
Popular Rivet Materials
The most common rivet materials used in CNC machining include:
- Aluminum - Lightweight, corrosion resistant, and easy to work with. Ideal for aircraft and high-performance applications.
- Steel - Very strong but heavier than aluminum. Used for high-stress applications.
- Titanium - Extremely strong yet lightweight. Used in the most demanding aerospace applications.
- Copper - Used for plumbing applications due to its corrosion resistance. Easy to machine and deform.
- Monel - A nickel-copper alloy that maintains strength at high temps. Used in harsh environments.
- Stainless Steel - Corrosion and heat resistant. Used in aggressive environments.
The choice of material depends on the specific application requirements. Aircraft grade aluminum is the most commonly used material for CNC workholding applications.
Key Rivet Attributes for CNC Workholding
Rivets used in jigs, fixtures, and other CNC workholding applications have some specific property requirements:
- Shear and tensile strength - Must withstand clamping forces without failing. Aircraft aluminum provides an ideal balance.
- Machinability - Should drill and deform smoothly without excessive force or tool wear.
- Grip range - Various grip lengths help join different stack heights. Standard rivets go from 1/8" to 5/8" grip.
- Diameter - Common sizes range from 3/32” to 1/4”. Custom diameters are available.
- Head styles - Countersunk, round head, brazier head, large flange head, and specialty head shapes.
- Alloy and temper - Affects strength, hardness, and machinability. 2024-T4 rivets optimized for machining.
- Lot traceability - For aerospace work, full traceability is required.
By selecting the optimal combination of these attributes, CNC shops can assemble high quality, precision workholding fixtures using rivets. This reduces build time compared to alternatives like screw machining.
Inspecting Rivets for Quality Assurance
All incoming rivets should be thoroughly inspected before being put into CNC production:
- Dimensional conformity - Confirm diameter, grip, head thickness, and other specs are met. This can be done by sampling parts from the lot.
- Surface defects - Visually inspect for dents, gouges, cracks, discoloration, or other flaws. Use a magnification lens if needed.
- Hardness testing - Spot check hardness values, which indicate proper alloy and consistent heat treatment.
- Certificate of Conformance - Supplier should provide documentation showing compliance with required standards and specifications.
By thoroughly vetting all incoming rivets, CNC shops can reject defective lots before they reach the production floor. This preventative quality step reduces scrapped work and downtime. Rivet inspection should be incorporated into the overall quality management system.
Sourcing High Quality Rivets for CNC Applications
Shopping around for the best source of CNC rivets is worth the effort. Here are some buying considerations:
- Specialization - Seek out rivet suppliers who cater specifically to the CNC machining sector rather than general hardware distributors. They'll have the best understanding of your requirements.
- Custom options - Many shops need non-standard diameters, grip lengths, head configurations, or materials. Choose a vendor that offers flexible customization.
- Certifications - Reputable rivet manufacturers will have AS9100, ISO 9001, or other certifications indicating adherence to strict quality standards.
- Domestic availability - For fast turnaround on orders, domestic US rivet suppliers are preferable unless offshore options can meet quick delivery demands.
- Technical expertise - Knowledgeable sales engineers should be available to help select the optimal rivet solution for your specific CNC applications.
By partnering with a qualified rivet supplier that caters to the CNC industry, manufacturers can ensure a smooth workflow and avoid production delays. Investing in quality rivets is one of the wisest decisions a CNC shop can make. CNC Milling CNC Machining