The Importance of High Quality Rivets in CNC Machining(feedrate Nicole)
- source:ESKRIDGE CNC Machining
What are Rivets?
A rivet is a mechanical fastener that consists of two parts - a smooth cylindrical shaft and a head. The shaft is inserted into a hole through the materials being fastened, and the head is smashed against the material using tremendous force. This force flattens and expands the rivet shaft, locking the rivet in place. The flattening also creates a second head, securing the materials together.
Rivets come in a variety of materials, including aluminum, steel, titanium, copper, and more. The material used depends on the application and necessary strength and corrosion resistance. Aluminum and steel are most common for CNC machining.
Key Properties of Quality Rivets
When selecting rivets for CNC machined parts, inspectors should look for several key properties:
- Strength - The rivet must be strong enough to withstand forces and impacts without bending, cracking or pulling loose. Aerospace grade aluminum is often used for high strength.
- Durability - Excellent rivets maintain their clamping force and integrity over years of vibrations, shocks, and temperature swings experienced by CNC machined parts like aircraft and autos.
- Shear Strength - This measures the force the rivet can withstand perpendicular to its axis. Rivets should have shear strength well above expected loads.
- Fatigue Strength - Indicates how well the rivet resists cracking from repeated loads over time. It's measured by rapid cyclic loading. Great rivets have excellent fatigue strength.
- Corrosion Resistance - Rivets must resist degradation from water exposure, road salts, cleaning chemicals and other corrosive agents during the CNC product's lifetime.
- Dimensional Consistency - All rivets in a batch should have uniform shaft diameters, head thicknesses, and other dimensions. Inconsistency leads to poor fit and performance.
- No Flaws - Cracks, voids, dents, weak spots and other flaws compromise the rivet's strength. Quality control eliminates defective rivets.
The Role of Rivets in CNC Machining
CNC machined parts often consist of multiple components fastened together. Rivets provide an adaptable, reliable, and cost-effective means of joining everything from non-structural panels to critical structural and aerodynamic components.
Here are some examples of how rivets are used in CNC machining:
- Aircraft - Rivets join the fuselage skin, ribs, stringers and frames. They also fasten control surfaces, landing gear doors, engine cowlings and more. Durability is mandatory.
- Automobiles - Body panels, trim pieces, bumpers, wheels and more are riveted in place for automotive CNC parts. Stainless steel resists corrosion.
- Electronics - CNC machined enclosures use rivets to assemble aluminum housings for computers, appliances and devices. Easy installation and good conductivity are priorities.
- Architectural Building Products - Panels for walls, canopies, railings and decoration rely on rivets for quick joining. The focus is aesthetics and function.
- Marine Vessels - Boats and ships are assembled from CNC parts using rivets. They unite fiberglass, steel and aluminum components while resisting saltwater corrosion.
As these examples illustrate, rivets may not be the most glamorous component, but CNC manufactured products would fall apart without them.
Optimal Riveting in CNC Machining
Achieving optimal riveting in CNC machined parts requires precision processes:
- CNC Hole Drilling - Holes are CNC drill-pressed to exact diameters. Consistency allows rivets to fill holes snugly.
- Part Fixturing - Parts must be firmly fixed in position so riveting force doesn't shift materials. Vacuum beds often hold aircraft components.
- Automated Feeding - Vibratory bowl feeders orient and sort rivets, feeding them to insertion tools. This saves time and reduces defects.
- Robotic Placement - Industrial robots repeatedly pick and place rivets in holes with accuracy and speed human assemblers can't achieve.
- Computer-Controlled Hammering - Pneumatic riveting systems use programmed pressure and striking force to flare rivet shafts consistently.
- Inspection - Automated vision systems confirm flushness, diameter, placement and other metrics to catch problems early.
When properly implemented, these methods enable fast, affordable, mistake-proof riveting during CNC production. This optimizes quality, strength and appearance.
The Bottom Line
From spacecraft to cars to buildings, rivets join countless CNC manufactured parts, making them linchpins of our constructed world. While diminutive, excellent rivets are vital to safety, performance and reliability. By selecting top-grade rivets and using precision CNC processes, manufacturers can guarantee their end products live up to the highest standards. CNC Milling CNC Machining