High Quality Rivets Essential for CNC Machined Parts(types of gear Paddy)
- source:GAENOR CNC Machining
Importance of Rivet Quality in CNC Machining
CNC (Computer Numerical Control) machining allows for incredibly precise manufacturing of components, particularly in the aerospace, automotive, and medical device industries. CNC machined parts include everything from gears, shafts, and couplings to plates, brackets, and casings.
Many CNC machined parts are held together with rivets because they offer a strong, permanent fastening solution. Rivets consist of a head and shank which are inserted into pre-drilled holes. The rivet shank expands when upset to create a tight interference fit.
Using poor quality rivets introduces potential defects into the CNC machining process. Common problems with low grade rivets include:
- Inadequate shear and tensile strength leading to joint failures
- Poor dimensional accuracy resulting in loose or poorly fitted rivets
- Substandard corrosion resistance causing weakened joints over time
- Poor workability making the riveting process difficult and inconsistent
When rivets fail in CNC machined products, it can lead to catastrophic breakdowns. Using high quality rivets optimized for the application is critical.
Standards for Quality Rivets
High performance rivets adhere to established standards that ensure they meet specifications for materials, dimensions, mechanical properties, and durability. Here are some of the key standards:
- ASTM F468: Standard specification for nonferrous bolts, hex cap screws, and studs. This covers material and property requirements for steel rivets.
- ASME B18.1: Standard for screw threads, threaded rods, yokes, and yoke ends. This provides specifications for rivet thread styles and quality.
- SAE J2270: Standard for fasteners used in high-temperature applications. It provides high temperature properties for rivets.
- AMS QQ-R-641: Aerospace standard that provides general riveting requirements including materials, treatments, and acceptance testing.
- ISO 15977: International standard covering tubular and split rivets for aviation applications.
Reputable rivet manufacturers test and validate that their products meet the required standards for reliable performance. This includes proof testing samples for shear strength, coatings adhesion, salt spray resistance, and other critical performance metrics.
Material and Design Considerations
The material and design of quality rivets depends on the specific application requirements. Here are some of the key considerations for material selection:
- Strength: Aircraft-grade aluminum, titanium, and steels are common. Strength is needed to meet shear loads.
- Temperature resistance: Alloys and coatings withstand high operating temps for engines and machinery.
- Corrosion resistance: Stainless steel, aluminum, and nickel alloys for marine and other wet environments.
- Weight savings: Lightweight aluminum, titanium, or polymers help reduce weight in vehicles.
- Fatigue life: High-cycle steels and alloys prevent cracking from repetitive loads.
The rivet design must also suit the joint design and service conditions:
- Solid or blind rivets: Cannot be installed from one side only. Require access to both sides of a joint.
- Tubular rivets: Can be closed from one side for access to only one side of a joint.
- Drive styles: Countersunk, buttonhead, flathead, universal head. Drives are optimized for installation tools.
- Grip range: Length of uncompressed shank for different material stack-ups. Standard and long grips.
- Diameter: Shank diameter determines hole size and influences grip strength. Common sizes from 1/16” to 5/16”.
By selecting the optimal combination of rivet material, design, and features, manufacturers can achieve strong and reliable joints in their CNC products.
Quality Control for Reliable Performance
Trustworthy rivet suppliers have rigorous quality control and validation processes to verify excellence:
- Raw material certification: Chemistry, mechanical properties, and quality control testing of incoming metal for rivet wire.
- Dimensional inspection: Sample testing and statistical process control to validate diameter, head style, length, grip and other dimensions are within specification.
- Mechanical testing: Shear, tensile, and fatigue testing of rivet samples from production runs.
- Surface quality: Examination of surface finish, markings, head formation, flash, and other defects.
- Sorting and packaging: Precise sorting of rivets by diameter, grip length, and features. Proper packaging prevents damage.
- Batch traceability: Detailed records linking production batches to raw material lots and QC testing results.
- Certification: Certificate of Conformance documents proof of compliance with required standards.
Reputable rivet manufacturers stand behind their products, often providing warranties against defects. They also conduct failure analysis when needed to improve quality going forward.
Get High Quality Rivets for Your CNC Components
Quality rivets are a simple but critical factor in achieving safe and reliable CNC machined products. By choosing a trusted supplier that validates rivet quality, manufacturers can avoid problems like joint failures or installation issues down the line. Be sure to review material specifications, design features, quality certifications, and testing data when sourcing rivets for your CNC machining needs. Investing in high quality rivets brings peace of mind and delivers optimized part performance. CNC Milling CNC Machining