When evaluating an impact riveting application, most engineers focus on the rivet itself.

Questions like these are common:

• What rivet diameter are we using?

• What material is being joined?

• How much capacity does the machine need?

While those are important considerations, they're only part of the equation.

Sometimes the biggest challenge isn't setting the rivet. It's reaching it.

A machine may have more than enough capacity to form the rivet, but if it can't physically access the riveting location, the application can become difficult, inefficient, or even impossible to assemble.

That's where throat depth becomes an important consideration.

What Is Throat Depth?

Throat depth is the distance from the machine frame to the tooling location.

It determines how far into a part or assembly the machine can reach to perform the riveting operation.

While often overlooked during initial equipment selection, throat depth can have a significant impact on fixture design, operator ergonomics, and overall production efficiency.

If the riveting location is positioned beyond the machine's available reach, manufacturers are often forced to:

• Reposition the assembly multiple times

• Change the assembly process

• Move to a different machine platform

• Consider custom equipment

In many cases, the machine has the capacity to perform the operation. The challenge is simply accessing the location where the rivet needs to be installed.

When Does Throat Depth Become a Problem?

Throat depth becomes increasingly important as assemblies get larger.

Examples include:

• HVAC products

• Appliance assemblies

• Doors and panels

• Electrical enclosures

• Furniture components

• Automotive assemblies

• Aerospace structures

• Large sheet metal fabrications

In these applications, the riveting location may be positioned well inside the assembly rather than near the edge.

The rivet itself may be relatively small and require only modest machine capacity. However, if the riveting location is 18, 20, or 24 inches from the edge of the part, a standard throat depth may not provide enough access.

This creates a situation where reach, not force, is the limiting factor.

Why More Capacity Isn't Always the Answer

A common assumption is that if additional reach is needed, a larger machine is the answer.

But larger machines are typically designed to provide additional capacity, not just additional throat depth.

As a result, manufacturers may end up purchasing a machine that exceeds their actual riveting requirements simply to gain the reach needed for the application.

That can mean:

• A larger machine footprint

• Increased equipment cost

• More capacity than the application requires

In these situations, what manufacturers often need is not a bigger riveter. They need a deeper throat.

A Real-World Example

This challenge recently came up with an HVAC manufacturer.

The application utilized a .120-inch diameter rivet that fit comfortably within the capacity range of the Milford 256 Impact Riveter. However, several of the riveting locations required nearly 20 inches of reach.

Historically, the customer would have needed to move up to the Milford 305 series simply to gain access to a 24-inch throat depth option.

The issue wasn't capacity.

The issue was reach.

To address this need, Orbitform developed a new 24-inch throat depth configuration for the Milford 256, allowing customers to match machine capacity to the application while still achieving the required reach.

24-Throat Options Across the Milford Product Line

Historically, customers requiring a 24-inch throat depth were limited to the larger Milford 305 and 405 models.

With the introduction of the Milford 256-24, manufacturers now have access to a 24-inch throat option across Orbitform's complete line of pedestal-style Milford impact riveters.

This provides greater flexibility when selecting equipment.

Instead of choosing a machine solely to obtain additional reach, customers can now select the machine capacity that best fits their application while still obtaining the throat depth they need.

Common Misconceptions About Deep-Throat Impact Riveters

"A larger throat means I need a larger machine."

Not necessarily.

Machine capacity and throat depth are two different considerations. Many applications require additional reach without requiring additional riveting capacity.

"Deep-throat machines must be custom."

While custom solutions are sometimes required, deep-throat impact riveters are available as standard configurations within the Milford product line.

Manufacturers no longer need to assume that additional reach automatically means a custom machine project.

"A deeper throat reduces machine performance."

A larger throat depth requires a more robust frame design, but properly engineered equipment can provide the necessary reach without compromising performance.

The objective is to maintain the rigidity and repeatability needed for consistent assembly while extending the machine's working envelope.

Is a Deep-Throat Impact Riveter Right for Your Application?

A deep-throat impact riveter may be a good fit when:

• Riveting locations are positioned far from the edge of the assembly

• Large panels or enclosures are being assembled

• Reach is the primary challenge, not machine capacity

• Operators are currently repositioning parts to access riveting locations

• Production efficiency is being impacted by machine access limitations

Not every application requires a deep-throat machine.

However, when reach becomes the limiting factor, throat depth can be just as important as machine capacity when selecting the right equipment.

Why Manufacturers Continue to Choose Milford Impact Riveters

Since Orbitform acquired the Milford product line in 2004, manufacturers have relied on Milford impact riveters for high-speed assembly applications across a wide range of industries.

Key advantages include:

• Proven electro-mechanical flywheel design

• Automatic rivet feeding

• Multiple machine capacities

• Multiple throat depth options

• Safety guarding and automation options

• In-house tooling and application support

The addition of the 24-inch throat Milford 256 expands those capabilities even further, giving manufacturers another option when balancing reach, capacity, and cost.

Final Takeaway

When specifying an impact riveter, capacity is only part of the equation.

Capacity determines whether the machine can set the rivet.

Throat depth determines whether the machine can reach it.

For manufacturers working with larger assemblies, doors, panels, enclosures, and other applications where riveting locations are positioned deep within the workpiece, throat depth can be the deciding factor in equipment selection.

With 24-inch throat depth options now available across the Milford 256, 305, and 405 product lines, Orbitform offers manufacturers greater flexibility to match machine size, capacity, and reach to their specific application requirements.

Not sure what throat depth your application requires? Contact Orbitform to discuss your assembly requirements and determine the right Milford impact riveting solution for your application.