High Quality Rivets for Precision CNC Machining(brass vs. bronze Gustave)
- source:BAGANZ CNC Machining
What Makes a Quality Rivet?
A quality rivet for CNC machining has the following key features:
- Tight dimensional tolerances - Quality rivets have an accurately controlled shank diameter, head height, and other critical dimensions. This allows for a snug, secure fit into CNC machined holes.
- High shear and tensile strength - Aircraft and aerospace rivets are noted for high strength, but other quality rivets also have adequate shear and tensile strength for securing parts together.
- Consistent hardness - A uniform hardness level helps the rivet resist damage during installation and use.
- Smooth finish - Any irregularities on the surface can impact the installation and performance. Quality rivets have a smooth, consistent finish.
- No burrs or defects - Flaws in the rivet can cause issues when installing into precision CNC machined components. Quality control eliminates defects.
- Made from durable materials - Steel, aluminum, titanium, and specialty alloys are common rivet materials selected for strength and corrosion resistance.
Major Types of Rivets for CNC Machining
There are several major varieties of rivets suitable for CNC machined components:
Blind Rivets - These rivets are installed from one side when access to both sides is not possible. Blind rivets come in break mandrel and break stem formats.
Solid Rivets - Offering the highest strength, solid shank rivets require access to both sides of a joint. They are commonly used in aircraft assembly.
Split Rivets - These rivets have a split shank that is expanded by a setting tool. The head fits into a countersunk hole.
Drive Rivets - Installed using a hammer rather than specialized setting tool, drive rivets are versatile low-cost general purpose rivets.
Structural Rivets - Designed for joining structural materials, these rivets have extra shear and tensile strength.
Flush Rivets - The head fits entirely within the hole for a smooth finish. Typically requires access to both sides.
Multi-Grip Rivets - This variation can accommodate small differences in material thickness thanks to multiple shank diameters.
Rivet Materials for Strength, Weight, and Corrosion Resistance
The rivet material must be matched to the design loads and service environment. Common rivet materials include:
Aluminum - Aircraft rivets are typically aluminum for light weight and strength. Various alloys help resist corrosion. Easy to install.
Steel - Known for high tensile strength. Low carbon and stainless varieties resist corrosion. Adds weight.
Titanium - Extremely strong but light weight titanium alloy rivets are used in demanding aerospace applications.
Copper - Used for rivets in electrical applications as copper is non-sparking and conducts electricity. Also found in heating and plumbing.
Monel - This nickel alloy offers strength, corrosion resistance, and non-magnetic properties for marine and other severe environments.
Plastics - Light weight plastic rivets have low strength limits but are useful as non-marring fasteners in electronics and appliances.
Rivet Strength Grades for Design Flexibility
Engineers select rivets based on required shear and tensile strength. Common grades include:
AD43XX - 2XXX series aluminum rivets with 43,000 psi shear strength for aircraft and aerospace.
AD5XXX - 5000 series aluminum rivets with 55,000 psi minimum shear strength.
C51XX - 5100 series aluminum structural rivets with 51,000 psi shear strength.
MS20470 - High strength steel rivets that meet demanding military specifications.
NAS1097 - Originally designed for aircraft, these steel rivets come in multiple strength grades.
Monel 400 - Nickel-copper rivets with 40,000 psi shear and 80,000 psi tensile strength.
The choice of rivet style and material grade provides extensive strength options for CNC machined components.
Proper Installation of Rivets
To achieve full rivet strength, proper installation technique is critical:
- Hole diameter should match the rivet shank with tight tolerances.
- Hole preparation must be free of burrs, shavings, oils, or moisture.
- Surface contact areas require flat support for uniform load transfer.
- Correct tools specific to the rivet style should be utilized.
- Set force should be adjusted not to under-compress or damage the rivet.
- Blind rivets are set when the mandrel snaps or stem pulls off.
- Solid rivets are fully set when the shop head is formed on the back side.
- Set rivets should be visually inspected for proper installation.
By following quality processes, the installed rivets will achieve maximum strength.
Sourcing Quality Rivets for CNC Machining
For demanding CNC machining applications, precision-made rivets from reputable manufacturers are recommended:
- Cherry Aerospace - Offers a wide selection of blind and solid rivets to aerospace standards.
- Falcon Fastening - Distributes a range of aluminum, steel, and specialty rivets.
- L.A. Rivet Company - Supplier of Mil-Spec and aerospace rivets since 1917.
- Ace Rivet - Large inventory of rivets for aircraft, military vehicles, rail cars, and construction equipment.
- National Rivet & Manufacturing - Rivet supplier offering extensive materials and strength selections.
Quality rivets specifically engineered for precision joining of CNC machined components are available from these and other industrial distributors.
From blind rivets used in electronic enclosures to structural rivets for helicopter landing gear, selecting the optimal rivets is a critical decision in CNC machined product design. With an understanding of rivet attributes and quality criteria, engineers can make informed choices on rivet type, materials, strength, and sourcing to produce a robust CNC machined assembly. Paying attention to proper rivet selection and installation practices will result in durable, high performance products. CNC Milling