Producing High Quality Rivets for CNC Machines(revits Tom)
- source:ZIEG CNC Machining
Rivets are a crucial component in many manufacturing and construction applications. With computer numerical control (CNC) machining, rivets can be produced to exacting specifications efficiently and consistently. This article will explore how to manufacture top-quality rivets optimized for CNC equipment.
What Are Rivets and How Are They Used?
A rivet is a mechanical fastener that consists of two main parts - a cylindrical shaft and a head. Rivets are inserted through holes in two or more materials, and the shaft is then deformed to create a permanent joint. The deformation process is called riveting or setting the rivet.
Rivets have been used for centuries in manufacturing and construction. Today, they are ubiquitous in aerospace, automotive, electronics, bridges, oil rigs, pipelines, and more. Rivets create strong joints without requiring welding or gluing. This makes assembly and repairs simpler. Popular rivet materials include aluminum, steel, copper, and Monel.
Optimizing Rivet Design for CNC
To maximize rivet quality and performance on CNC equipment, several design factors should be considered:
- Diameter - The rivet shaft diameter must match the precise hole diameter of the materials being joined. Tolerance should be +/- 0.002 inches or less.
- Length - Rivet length should allow the set head to be flush with or slightly below the material surface. Length tolerances around +/- 0.005 inches are recommended.
- Head shape - Various head shapes like round, brazier, countersunk, and modified brazier are available. The choice depends on hole type, material thickness, and assembly method.
- Material - Aircraft-grade aluminum alloys are common for CNC rivets. However, steel, copper, Monel, and titanium may also be used. The material must be machinable and ductile.
- Mechanical properties - Tensile strength, shear strength and fatigue resistance should be maximized within alloy specifications.
- Consistency - Diameter, length, head dimensions, material, and strength should have minimal deviations for reliable performance.
Manufacturing Quality Rivets on CNC Machines
Producing exceptional quality rivets on CNC machines involves following a precise manufacturing process:
- Sourcing - Start with raw material rod stock that meets target diameter, circularity, straightness, and alloy specifications. Aerospace-grade 6061 aluminum is a popular choice. Inspect chemistry and properties with spectrometry and tensile testing.
- Facing - The rod end is faced on a CNC lathe to achieve a clean, perpendicular edge for further machining. This improves concentricity.
- Turning - A CNC lathe precisely turns down the rod to the required rivet shaft diameter and length. Tolerances of +/- 0.001 inches or better can be held.
- Head forming - The rivet head is forged into shape on a CNC header. This cold forging process compresses the material to flow into the header die.
- Heat treating - Rivets are often heat treated and aged to maximize strength, hardness, and durability. Solution treatment, quenching, and aging in ovens produce consistent results.
- Quality checks - Dimensional tolerances are verified with gauges, micrometers, and optical comparators. Rockwell hardness and tensile tests confirm mechanical properties.
- Coating - Certain rivets are coated to resist corrosion and chemicals. Common coatings are zinc, cadmium, and passivation. They are applied through plating, vapor deposition, and other methods.
From raw material selection through final inspection, meticulous care must be taken when manufacturing rivets destined for precision CNC applications. When the proper alloys, dimensions, consistency, and properties are achieved, the resulting rivets will perform flawlessly during automated assembly. Investing in quality tooling and validated CNC processes is key to rivet production success. With attention to detail, manufacturers can keep their customers’ supply chains running smoothly. CNC Milling CNC Machining