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Findings of Farold Hoover regarding the Griswold number 10 cast iron skillet with grooved handle listed on eBay by Jerome “Shane” Cooper

By Farold Hoover[1]

My background:

I have been a machinist, tool designer, and programmer involved in engineering for more than 33 years. I have made everything from Boeing cockpit window frames to aircraft-on-ground time-critical parts in the spare parts market.

In 2009 I opened my own tooling shop in Oxford, Kansas; ProMachine Engineering. My company specializes in machining close tolerance parts, building the tooling for aircraft companies to manufacture sheet metal parts, and building the tooling to locate and hold raw material and castings for machining.

I also manufacture molds for carbon fiber masts, fuselages, and wings for professional wind surf teams in California. This process requires significant hand-finishing using sanding and die grinders to obtain a mirror finish on the mold without altering the original geometry of the computer generated data (CAD) provided by the teams.

I hold a 2-year degree in machine technologies that was granted in 1985 by Pittsburg State University, Pittsburg Kansas.

I am also a vintage cast iron researcher and collector. While I do collect other iron, my primary focus is waffle irons; particularly Stover-made pieces.

Review of the Griswold small logo number 10 skillet with grooved handle:

I have reviewed the original-high-resolution photographs of the skillet that were taken by Mary Theisen on November 28, 2018. My purpose in this review was to see if I could determine whether this particular skillet had been machined. It is possible that a cast iron skillet could be machined. It would take the work of a very skilled machinist, however, and would leave signs that the skillet had been altered.

1. Examination of the corner radius on the groove near the side of the skillet.

[pic]

[pic]

This radius is particularly small. It would require a very small end mill (possibly 1/8” diameter) to make this cut. As 1/8” end mills are short, it would require a very small tool to hold the end mill.

Similar to a drill bit, an end mill is placed within a holder, typically called a “collet.” As with a chuck and drill bit, the holder of the end mill is larger in diameter than the end mill itself. Given the particular radius shown in the photo above, with the size of end mill that would be required to make this cut, the collet would have collided with the skillet wall. Therefore, I do not believe that this tight of a radius to the skillet wall could have been made with an end mill.

A die grinder could have been used to clean up the corners, but I see no sign that this was the case. Unless it was the work of a very experienced tool builder, signs would remain showing that a die grinder had been used. These tools are non-forgiving and will gouge a piece very easily.

2. Examination of the cluster of short scratches that Mary observed on the handle.

Upon close examination of the the original photographs, I can see that there is casting grain over the scratches. As this casting grain is present, the original pattern used to mold the skillet is the cause of this cluster of scratches and not a machine.

My theory (and this is a only a theory) is that this skillet was cast from a prototype pattern that was not fully finished. Making a pattern is very labor intensive. In my experience, most companies will cast from a prototype pattern before putting the hours in to making the master pattern for production patterns.

3. Examination of the grain in the groove of the handle.

Some have speculated that the groove in the handle appears too “smooth” as compared to known Griswold grooved handle skillets. I compared the grain pattern in the groove to the other areas of this skillet. The grain pattern on the interior of the groove and the outer skillet handle are close in comparison; both have quality casting surfaces.

4. Examination of the casting flaw in the groove of the handle:

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I examined the photos for casting flaws that could not be replicated mechanically or by hand. The photos show a small casting flaw in the groove near the skillet wall. Upon close examination, the flaw has sharp corners.[2] In my opinion, this flaw was not manually added.

Conclusion

In my opinion, this number 10 Griswold small logo skillet with grooved handle was cast as it is now seen. It is an authentic Griswold piece. I render this opinion to a degree of 99.9%. Put another way, to a reasonable degree of mechanical certainty, this pan is authentic.

It would take many hours by a very skilled machinist with the proper machinery to have created the groove in this handle from a non-grooved handle. While it would not be impossible to do, it would be very costly and evidence would have been left that the skillet had been altered. I see no sign that this skillet has been altered from the original casting. Moreover, when the pattern for this skillet was first made, there was no computerized numerical control (CNC) equipment[3] or CAD data in existence. Thus, every pattern would vary to some degree, no matter how slight.

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[1] Original writing edited by Mary Theisen for clarity. Revisions have been reviewed and approved by Farold Hoover.

[2] If you think of marks that would be left by a tiny wadded up sheet of paper, that is similar to the marks on the interior of the casting flaw; many angles and sharp corners. In my opinion the only way this could have been caused if the pan had its handle machined is if there was a void, or air bubble, within the iron itself; or use of poor-quality iron such as that recycled by a scrap yard. If this had been the case, evidence would have been left showing it had been machined.

[3] A CNC machine is one which has automated movement which is controlled by a computer. These machines were not widely used until the 1970s.

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