High Quality Rivets for CNC Machining(manual cnc machine Claire)
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- source:DALLMAN CNC Machining
What is a Rivet?
A rivet is a mechanical fastener that connects two or more pieces of material by inserting a metal shaft through aligned holes in the pieces and forming a head on one or both ends. The rivet holds the materials together through friction and pressure exerted by the deformed shaft on the hole walls.
Rivets come in a variety of head shapes, materials, lengths and diameters. Some common types include blind rivets, tubular rivets, semi-tubular rivets, split rivets, and drive rivets. The choice of rivet depends on the application requirements like joint strength, accessibility, and assembly method.
Key Properties of Quality Rivets
For CNC machining applications, rivets must meet exacting standards for dimensions, strength, and consistency. Here are some of the most important properties of high quality rivets:
- Precise Dimensions: Rivet shafts and heads must be manufactured to tight tolerances, often within a few thousandths of an inch. This ensures rivets fit properly into pre-drilled holes.
- High Shear and Tensile Strength: Rivets must resist shearing forces that act to laterally separate joined materials. Tensile strength enables rivets to withstand axial pulling/stretching loads without failing. Stronger rivets provide more reliable connections.
- Consistent Hardness: The rivet head and shank should have a uniform hardness for even deformation when setting the rivet. Inconsistent hardness can cause cracking or improper rivet formation.
- Excellent Ductility: Ductile materials like aluminum or mild steel can stretch and deform when setting a rivet without fracturing. Brittle materials are more prone to cracking.
- Corrosion Resistance: Rivets must maintain their strength and functionality when exposed to weather, salt spray, chemicals and other corrosive influences present in many CNC machining environments. Stainless steel offers excellent corrosion resistance.
- Wear Resistance: Friction from movement between joined parts can erode some rivet materials. Wear-resistant rivet materials like titanium retain high strength after years of abrasive contact.
How Quality Rivets Are Manufactured
Producing rivets to the demanding specifications required for CNC operations necessitates advanced manufacturing techniques and quality control. Here is an overview of how high-grade rivets are made:
Raw Material - High strength metals like steel, aluminum, copper and titanium are formed into rods, wires or bars stock for rivet production. Aircraft quality rivets often use more exotic alloys. The raw stock must have a fine-grained uniform microstructure free of voids and inclusions that can weaken the rivet.
Heading - Rivet blanks are precisely cut to length from the raw wire or rod stock, usually by computer-programmed automatic machines. These blanks are then headed, which forms the rivet head using dies in a heading machine. Heading produces a head shape that is optimized for both installation and strength.
Shank Processing - Additional processes help improve rivet shank properties. Cold forging may compress and harden the shank. Annealing can refine the grain structure. Shot peening induces beneficial compressive stresses on the outer shank surface.
Hardness Testing – Rockwell, Vickers or Brinell hardness tests measure rivet hardness values on the head and shank. This verifies hardness is within specifications and consistent from rivet-to-rivet.
Plating – Many rivets are plated with zinc, cadmium, tin or other metals to improve corrosion resistance and lubricity during driving. A chromate conversion coating may be applied atop plating for an added layer of corrosion protection.
Final Quality Inspection – Dimensional inspection using optical comparators,Coordinate Measuring Machines or other precision metrology tools verifies rivet head and shank dimensions are within tolerance. Testing may also cover shear strength, tensile strength, pull-out force and other mechanical properties.
Proper packaging – For bulk quantities, rivets are carefully packaged in boxes, bags or barrels to avoid damage during handling and shipment that could cause jamming during automated installation.
By following this rigorous production and inspection regimen, rivet manufacturers can produce superior quality fasteners that are perfectly suited to performing reliably in CNC machined components and assemblies.
Quality Rivets Enable High-Precision CNC Machining
The automated nature of CNC machining demands consistency and precision that only the highest quality rivets can deliver. Here are some of the key benefits of using top-tier rivets in CNC operations:
- Smooth Feeding – Consistent rivet dimensions prevent jamming, misfeeds or machine stoppages that waste production time and labor.
- Optimized Fit – Precisely sized rivet shanks and holes align perfectly for rapid insertion by automated equipment.
- Automation Compatibility – Robotic riveting machines function optimally with rivets having uniform hardness and geometries.
- High Clamping Force – Strong and ductile rivets provide superior joint compression strength and fatigue life.
- Damage Resistance – Wear-resistant materials withstand abrasion from movement between parts without losing clamping capability.
- Corrosion Protection – Plating and alloy composition help rivets retain strength in wet environments or when exposed to chemicals.
By utilizing quality rivets designed for the demands of automated production, CNC machined products will have durable, reliable fastened joints. The small added cost per rivet is more than justified by the performance benefits and prevention of scrapped parts or production downtime. With a knowledgeable rivet supplier, CNC shops can enjoy smooth automated riveting and assemble high-quality finished products. CNC Milling CNC Machining