Producing High Quality Rivets with CNC Machining (plastic resin for injection molding Tabitha)

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Rivets are a critical component in many manufacturing and construction applications. Though seemingly simple, high quality rivets require careful engineering and production methods to ensure strength, consistency and reliability. CNC machining offers an efficient, precise approach to manufacturing rivets with the tight tolerances and repeatability needed for quality control.
In this article, we’ll look at how CNC machining is used to produce top-notch rivets. We’ll cover rivet design considerations, CNC machining processes, quality control steps, and advantages over other manufacturing techniques. Whether you’re a designer, manufacturer or purchaser of rivets, understanding CNC machined rivet production will help you specify and source optimized rivet components.
Rivet Design Factors
Several design factors must be considered when engineering rivets for CNC machined production. These include:
- Head shape and size - Round, flat and countersunk heads in various diameters are common. The head must withstand force during installation.
- Shank length and diameter - This depends on the thickness of materials being joined. Longer shanks allow for deeper engagement.
- Alloy selection - Aircraft grade aluminum alloys are commonly used. This balances strength, weight and cost.
- Break edge and residual shank design - For blind rivets, the break edge and residual shank profile impacts installation and removal.
- Grip range - The clamping range based on minimum and maximum material thickness the rivet can engage with.
- Specifications - Relevant rivet specs must be met, which may include military, aviation, automotive or other standards.
CNC Machining Processes for Rivet Production
CNC machining is well suited to producing rivets thanks to its:
- Automation - CNC programs allow for automatic, unattended machining once proven out.
- Consistency - CNC ensures every rivet meets the exact same specs, critical for both installation and quality assurance.
- Accuracy - Complex programming precisely controls dimensions, hole location, head shape and break edge profiles.
- Speed - CNC machining has high production rates compared to manual machining or other rivet forming processes.
The two main CNC machining processes used are milling and turning.
CNC Milling:
Milling machines use rotating cutting tools to slice away material. Common approaches include:
- 2-3 axis milling of the rivet head - The programmed toolpath shapes the precisely contoured head profile.
- Drilling rivet shank holes - Either performed on a CNC mill or CNC drill machine.
- 5-axis milling of break edge and residual shank - The complex 3D shapes are machined with simultaneous 5-axis motion.

CNC Turning:
Turning creates rotationally symmetric features by rotating the part against a stationary cutting tool. This includes:
- Turning the main shank diameter - The tool cuts the outer profile as it rotates.
- Forming head features - Cutting tools profile recessed and protruding head features.
- Parting off completed rivets - A blade cuts each rivet from the barstock to length.

Secondary processes like deburring, heat treatment, surface treatments and quality testing are also implemented. The specific CNC operations are programmed for each custom rivet design.
Quality Control and Inspection
Stringent quality control ensures reliable CNC machined rivets. Typical inspection steps include:
- First article inspection - The first production sample is thoroughly measured to verify conformance with specifications.
- Dimensional inspection - Sample testing validates critical dimensions like head diameter, shank length and grip range. Go/no-go gauging is common.
- Metallurgical testing - Composition and heat treatment is analyzed per material certifications and specific alloy requirements.
- Head tensile testing - Rivet heads are pulled or shear tested to confirm proper tensile strength.
- Break test – Blinded rivets have the shank pulled to validate break edge and residual shank geometry.
- Visual inspection - Samples are visually examined for surface defects under a microscope.
By comprehensively testing and measuring production runs, any non-conforming rivets can be rejected before shipment.
Advantages of CNC Machined Rivets
CNC machining offers notable benefits over other rivet production approaches:
- Higher consistency and repeatability - CNC precision ensures minimal deviations.
- Increased strength - Optimized alloy selection and heat treatment.
- Lower per-unit cost at production volumes - Automated CNC is efficient for moderate to high volumes.
- Custom break edge profiles – Unique blind rivet break designs are machinable.
- Head shapes beyond basic domes - Unique flattened, countersunk and hex head profiles.
- No tooling required - CNC programs are easily modified for design revisions.
- Scalable production - Additional CNC machines can be added to increase capacity.
For designers and engineers specifying rivets, CNC machining can produce premium custom designs optimized for your specific application needs.
While CNC machining and quality processes require upfront planning, this investment pays dividends through highly capable, reliable rivets. Tight tolerances, optimized materials, stringent inspection and automation produce precision rivets at economical per-part costs. By understanding CNC rivet manufacturing, engineers can incorporate improved joining solutions into their designs. For manufacturers, mastering CNC rivet production opens new business opportunities across diverse assembly and fabrication industries. CNC Milling CNC Machining