Riveting in Sheet Metal Fabrication(what is a rivet Irene)
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What is a Rivet?
A rivet is a mechanical fastener that joins two or more materials by deforming its shank. The shank inserts through holes in the materials being fastened, and a head on one end is upset, or mushroomed outward, to clamp the materials together. The rivet shank expands, filling the holes and creating a solid connection.
Rivets come in many styles, materials, and sizes, but some of the most common types used in sheet metal fabrication include:
- Solid rivets - made of a single material like steel, aluminum, copper, or monel. The rivet head is upset with force, expanding the shank.
- Blind rivets - hollow and designed to be installed from one side of a joint. Pulling a mandrel through the rivet expands the blind side to create a head.
- Self-piercing rivets - pierce through stacked sheets of material rather than requiring pre-drilled holes. Often used for joining lightweight metals or composites.
- Drive rivets - have a pre-formed head on one end and are upset on the installation end to expand the shank. Quick to install but not removable.
Benefits of Riveting Sheet Metal
Riveting offers numerous advantages for joining sheet metal that make it a popular fastening method:
- Permanent - Once installed, solid rivets cannot be removed without destroying the rivet. This creates highly secure joints.
- Strength - The mushrooming of the rivet shank creates a strong mechanical connection that can withstand vibration, shock, and stress.
- Material versatility - Rivets come in a wide range of metals, making it possible to rivet dissimilar materials like aluminum and steel. Specialty rivets are also available for composites and plastics.
- Weight - Rivets add very little weight versus other fasteners like bolts or screws. This helps maintain a lighter assembly.
- No damage - Properly set rivets will not damage or distort thin sheet metal the way overtightened screws can.
- Appearance - Countersunk rivets result in a smooth, finished look. Riveting also avoids exposed threads or fastener heads.
- Automation - Rivet setting can be easily automated for speed and consistency in mass production environments.
When to Rivet Sheet Metal
Rivets work well for sheet metal applications like:
- Permanent sheet metal joints - Rivets create permanent, non-removable bonds ideal for one-time assembly. Riveting is faster than welding or adhesive bonding.
- Joints subject to vibration or shock loads - The mechanical clinching of rivets withstands these dynamic loads better than screws or bolts.
- High temperature environments - Certain specialty rivets work in extreme heat where adhesives would fail.
- Dissimilar material joints - Rivets like aluminum and steel can join different metals that may be hard to weld together.
- Quick fastening during mass production - Automated rivet setting allows fast joining for volume manufacturing.
- Thin sheet metal - Rivets avoid the material distortions caused by overtightening screws into thin sheets.
- Visual appearance - The smooth appearance of flush rivets provides a finished look not possible with exposed fasteners.
Keys to Successful Riveting
Proper rivet selection, hole size and placement, and installation technique help ensure robust sheet metal joints:
- Select the best rivet material and type - Consider strength, corrosion resistance, temperature requirements, and installation method.
- Drill hole diameter to match rivet size - Holes should tightly match the rivet shank before upsetting. Too large of a hole reduces strength.
- Position holes accurately - Rivets should be centered in the joint overlap with even margins around holes.
- Use proper installation tools - Set rivets using pneumatic squeezers, impact riveters, hammer sets, or presses to create consistent connections.
- Avoid damaging rivets - Dinged, bent, or damaged rivets should not be used since they may fail prematurely.
- Set rivets completely - Mushrooming the rivet shank until it fills the hole ensures maximum strength.
- Use washers if needed - Washers around hollow blind rivets can provide extra shear strength or improved appearance.
- Check for failed rivets - Confirm the rivet head shape and feel for any loose connections needing replaced.
By understanding when and how to apply rivets in sheet metal designs, manufacturers can take full advantage of this versatile, economical, and highly-reliable fastening method. Proper rivet joint design, material selection, and installation technique will lead to products with exceptional structural integrity. Riveting remains a valued fabrication process for producing durable sheet metal assemblies and components in almost any industry. CNC Milling CNC Machining