Quality Rivets for CNC Machining(3d print wall thickness Beau)
- source:GAENOR CNC Machining
What are Rivets?
A rivet is a mechanical fastener that consists of two main parts - the rivet body and mandrel. The body is a cylindrical shaft that flares out at one end into a round head. The mandrel is inserted into the hollow end of the rivet body and serves to spread the tail of the rivet when set.
Rivets work by placing the rivet body into a pre-drilled hole through two or more layers of material. The mandrel is then pulled, which causes the body to flare out and grip the layers tightly together. The excess mandrel is then sheared off, leaving the rivet head on one side and the flared tail on the other side to secure the materials.
Benefits of Rivets for CNC Machining
There are several reasons why rivets make an excellent fastening choice for CNC machined parts:
- High strength: Properly set rivets form a tight clinch between materials that can withstand substantial shear and tensile forces. The flare also creates stiffness and resistance to vibration.
- Consistency: Automated riveting with CNC machines ensures each rivet is set precisely and uniformly for reliable performance.
- Speed: Riveting is extremely fast with CNC equipment compared to other mechanical fastening methods like nuts and bolts. No threading or other prep work is required.
- Flexibility: With various head shapes/sizes and materials available, rivets can accommodate many joint requirements and material combinations.
- Cost: Rivets are very economical compared to welding or adhesive bonding techniques in most cases. Lower assembly labor also offsets costs.
- Disassembly: Rivets can generally be drilled out if needed for repairs or part separation. Other fasteners like bolts are often reused.
- Weight savings: Rivets are lightweight and eliminate the need for bulky nut plates and other hardware. This reduces part weight, which is beneficial in many applications.
Factors in Quality Rivets for CNC Machining
To achieve maximum performance and durability of CNC machined components, the following factors should be considered when selecting rivets:
- Aluminum - Best for joining aluminum or soft materials. Not recommended for high strength needs.
- Steel - Stronger and more durable than aluminum. Ideal for structural joints and high stress applications. Withstands vibration well.
- Monel - Excellent corrosion resistance while still moderately strong. Used for marine and other corrosive environments.
- Titanium - Very strong yet lightweight. Typically used in aerospace applications.
- Special alloys - Custom materials tailored for unique needs like high temperatures or chemically reactive conditions.
- Tensile strength - The amount of tension force a rivet can withstand before breaking. Measured in psi or N/mm2.
- Shear strength - The force a rivet can resist perpendicular to the axis before failure. Also measured in psi or N/mm2.
- Higher strength rivets should be used for dynamic loads and critical needs. Lower strength is acceptable for static, less demanding uses.
- Diameter tolerances of +/- .001" or less. Ensures consistent fit in pre-drilled holes.
- Concentricity of head to shank within .002" TIR. Allows uniform setting and clamping force.
- Straightness within .005" per inch. Prevents distortion which can compromise joint integrity.
- Aligned, cylindrically shaped legs after setting. Indicates proper flow and filling of hole.
- Smooth, uniform surface without dents, gouges, seams or sharp edges. Reduces risk of cracks initiating.
- Clean, oxide free surface. Allows tighter clinch and optimal bonding if adhesives are also used.
- Proper hardness. Should be soft enough for drilling/driving, but hard enough to resist damage during handling and setting.
- Round, flat, countersunk, modified, etc. Choice depends on clearance needs and appearance.
- Match head shape to rivet setter in CNC machine for proper setting.
In summary, choosing high quality rivets matched to the specific CNC machining application and materials leads to superior finished products. Precisely set rivets maximize joint integrity and service life. Consultation with a qualified rivet supplier is recommended to review joint requirements and select the optimal rivet type and specifications. With diligent rivet selection and automated precision setting, CNC machined components will meet quality and performance expectations. CNC Milling CNC Machining