A Proper Home for Bottom Tooling: My 1-Inch Hardie Tool Holder

After I made the Zero Point plate and set it up on my fly press, I turned my attention to the bottom tools I already owned.

My original thought was that the square pass-through in the plate could also serve as a Hardie hole. But once I started looking at how my existing Hardie tools would fit and bear against the plate, I realized that approach was going to cause problems.

The tools were all different.

Some fit the opening, while others were too large. Some had Hardie posts that tapered toward the bottom. Some transitioned into a uniformly flat underside beneath the working part of the tool, while others had rounded transitions between the post and the tool body.

There was no consistent fit or seating surface. Looking at those differences, I could see that using them directly in the opening would ultimately damage the Zero Point plate.

I had put too much work into creating a precision foundation to make that opening the weak point.

Leaving the anvil tools at the anvil

I wanted precision, uniformity, and function across my fly press bottom tooling. Trying to accommodate every variation in the tools I already owned was not going to get me there.

Instead, I left those tools for use at the anvil and made a dedicated bottom tool holder. It would become the foundation for future Hardie tools made specifically for my fly press.

That was an important change in direction. Rather than designing around a collection of inconsistent tools, I could establish a common interface and make each new tool to match it.

The holder and its tooling would be parts of the same system.

Developing the holder

I made the holder from hardened and tempered 4140 steel, providing a dedicated interface between the Hardie tool and the base plate.

There were a few prototypes along the way, including versions with different retaining-screw threads. I eventually settled on M10 × 1.5.

That is slightly larger in nominal diameter than 3/8"-16, and it carries forward the thread standard I use on the Zero Point base plate. Keeping that detail consistent made sense for the system I was building.

The 1-inch Hardie opening also follows a specific profile with rounded corners. It is made to fit my Power Forge bottom tools, not every tool with a nominally 1-inch square post.

That distinction comes directly from what I learned with my original tools: a size description alone does not establish a consistent fit.

Making room for toe clamps

My original holder did not have purchase for toe clamps. It worked with my Zero Point arrangement, but that limited its usefulness for someone who did not have my base plate.

I revised the design to include stepped sides, giving toe clamps a place to engage.

That opened up another way to mount the holder. Someone could use it as the foundation for compatible bottom tooling without first adopting the Zero Point plate.

The precision tool interface stayed the same. The mounting options became more flexible.

The same philosophy, above and below

The bottom tool holder follows the same precision philosophy as the specialty tool holder in my ram.

I harden and temper my bottom tools with the intention of making tooling that will last a lifetime. Just as importantly, I make each Hardie post to the same dimensions and profile, so the fit is consistent from one tool to the next.

Each compatible bottom Hardie tool indexes into the holder and lines up with the top tooling. I am not starting over with a different fit every time I change tools.

On the Zero Point setup, that alignment is also retained when the holder is removed and returned to its indexed position.

Other bottom tools in the system mount directly to the Zero Point plate rather than using the Hardie holder. Those tools follow the same principle: repeatable positioning in X and Y, keeping them centered beneath the ram.

The mounting method may differ, but the goal does not.

Building an ecosystem, not just individual tools

The Zero Point plate, the top tool holder, and the bottom Hardie tool holder are not isolated projects. They are connected parts of the way I want my fly press to work.

The plate establishes the location. The holders provide consistent interfaces. The tools are made to fit those interfaces.

My existing anvil tools helped me recognize why that consistency mattered. They were different tools with different fits, and trying to make the plate accommodate all of them would have worked against the precision I was trying to achieve.

Making a dedicated holder gave me a standard to build on.

Precision and repeatability are not just extra features in this setup. They are what allow the Zero Point ecosystem to work.