All About Aluminum Rivnuts: What They Are, Types, Uses & Installation

What are Aluminum Rivnuts?

Aluminum rivnuts, sometimes called aluminum threaded inserts or rivet nuts, are a type of fastener used to create strong, reusable threaded holes in thin sheets of material like aluminum, steel, fiberglass, and plastic. They allow you to securely fasten bolts where only a thin sheet is available and offer many advantages over standard nuts and bolts.

How Do Aluminum Rivnuts Work?

An aluminum rivnut consists of a threaded aluminum or steel barrel that flares out into a wide flange at the bottom. To install it, you first drill a hole that's slightly smaller than the barrel. You insert the rivnut into the hole and use a special rivnut tool that pulls on the inside of the barrel with enough force that the bottom flange flares outward, clamping the sheet tightly between the flared flange and the top head of the rivnut.

This creates a permanent, reusable threaded insert that lets you fasten bolts securely. The threaded barrel and strong flange withstand tremendous shear and pullout forces, while distributing pressure evenly over a wide area underneath the sheet.

Benefits of Using Aluminum Rivnuts

Compared to standard nuts and bolts, aluminum rivnuts provide many advantages:

• Much greater holding strength since they spread force over a wider area
• No need to access the backside of the material you're fastening to
• Smooth backside surface with no protruding bolts
• Reusable threads that won't wear out as easily over time
• More vibration resistance from solidly clamped threads
• Quick and easy one-sided installation
• More aesthetic clean look compared to bulky bolts

Types of Aluminum Rivnuts

There are several varieties of aluminum rivnuts to suit different needs:

Standard

The most common style, these classic rivnuts have a threaded aluminum or steel barrel and large flange ideal for thin sheets of metal and fiberglass.

Large Flange

Featuring an extra wide flange, these rivnuts distribute clamping force over an expanded area for maximum strength and load capacity.

Countersunk

With an inverted cone shape under the head, these rivets can be installed flush in countersunk holes for smooth surfaces.

Breakstem

Also called break pull rivnuts, the inner stem breaks off flush after installation for fast blind side attachments.

Self Plugging

These inserts seal over after fastener removal for leak-proof fluid system panels like aerospace and auto designs.

High Strength

Engineered from harder aerospace grade aluminum alloys or tough aircraft steel, these heavy duty rivets withstand extreme loads.

Aluminum Rivnut Tools

While a regular hammer can work with some hand operated rivnuts, specialized tools help make installation much easier and expand the flange fully to maximize strength. Electric, pneumatic, or hydraulic rivnut tools rapidly pull the stem and flare out the flange.

Rivnut Hand Tools

Compact, easy to use tools for occasional jobs use levers, jaw pulls, or threaded stems drawn outward by wrench turning force. Most require drilling an access hole for the rotating mandrel shaft.

Blind Rivnut Tools

For blind side riveting where only one surface is accessible, these tools forcibly pull and then snap off the inner stem so no access hole drilling is needed.

Power Rivnut Tools

Fast electric or pneumatic power tools use strong hydraulic pressure to quickly install rivnuts by the hundreds for mass production. Auto-fed models feed and set rivets rapidly in assembly lines.

Installing Aluminum Rivnuts

Installing aluminum rivnuts to create strong, reusable metal threaded inserts only takes a few simple steps:

1. Clamp materials to drill through, or use a center punch to prevent walking
2. Drill hole slightly smaller than rivnut barrel diameter
3. Insert rivnut into hole flush with one side
4. Use rivnut tool to clamp flange tightly against opposite surface
5. Attach fasteners into the reusable rivnut threaded insert

Be careful drilling to exact diameters, thoroughly debur holes, hold rivnut perpendicular to surface while setting, and take safety precautions against flying metal shards and pinch points when using power tools.

Removing and Replacing Rivnuts

While designed for permanent installation, it is possible to drill out damaged aluminum rivnuts and replace them if needed. Use left-handed drill bits turning counterclockwise to extract the original insert, then redrill hole to clean up threads before inserting new rivnut.

Aluminum Rivnut Applications

Some common uses for reusable aluminum threaded inserts include:

• Aircraft and aerospace equipment
• Automotive panels, frames, trim
• Appliances and electronics cases
• HVAC ducting and equipment
• Heavy machinery access panels

Almost anywhere strong yet removable and reusable bolts are needed on sheet metal, aluminum rivnuts provide an ideal threaded fastener point. Their combination of strength, vibration resistance, and easy installation has made them a popular choice across manufacturing and repair industries.

FAQs

What materials can you install aluminum rivnuts in?

Aluminum rivnuts work well in thin sheets of aluminum, steel, stainless steel, fiberglass, plastic, and other rigid materials. The material must be rigid enough to tightly clamp the rivnut flange.

How thick of material can you use?

Standard aluminum rivnuts are made for material thickness up to about 1⁄4 inch (6mm). Special extra long barrel rivets are available to accommodate greater thicknesses if needed.

Is special tooling required to install rivnuts?

While possible to use a hammer for some riveting, a rivnut tool makes proper installation much easier and faster. Power tools provide the best results in most cases. Both handheld and bench style power tools are available.

Can I remove and replace broken rivnuts?

Yes, it is possible to drill out damaged rivets and install new inserts. Use left-handed bits to back out remains of old rivet, clean hole threads, then insert new rivnut.

Do rivnuts require accessing both sides of a panel?

Blind rivnut varieties allow installation from just one side, using tools that pull and break off the inner stem so no access hole is required on the opposite surface.