From the beginning, Field Company’s aim has been to make cast iron cookware that’s every bit as good as treasured vintage pieces—and for the same reasons. This required years of research and testing: To learn how to make ‘em like they used to, we had to, well, learn how they used to make ‘em.
Field Skillets start with the production of a “tool.” Think of the tool as a kind of master design: it’s a large, heavy piece of ductile iron exactly in the form of a Field Skillet, complete with the branding you see on the base of the pan. From the tool, we’re able to create a set of precise molds for a run of castings.
To create a mold, foundry workers pack specialized sand tightly around both sides of the Field Skillet tool, leaving small and precise gaps known as “gates.” At casting, 2500°F molten iron is poured through the gates and into the cavity created by the mold. As the liquid iron cools, it solidifies quickly, forming a casting in the basic shape of a Field Skillet.
Raw castings are rough and heavy, a far cry from the lighter, smoother cookware at the end of the production cycle, but they bear a few of the hallmarks of a Field Skillet right away.
What is a green sand casting?
Like vintage producers, we use “green sand” for our molds—a piece of lore we heard often was how the vintage pans used fine-grained sand from the banks of Lake Erie. Green sand doesn’t refer to its color; it means that the sand has not been set in place with heat, adhesive, or other processes. We use green sand castings to produce a smooth, vintage-style surface finish, in keeping with our forebears in cast iron manufacturing.
Shake, shake, shake
Once the raw casting has cooled enough to solidify, there’s still quite a bit of sand stuck to the casting that needs to be cleaned off. The next step is a “shake-out,” which is a fancy way of saying a machine jostles the castings around as they move along a belt, knocking off remaining fragments of the sand mold. This sand is recovered and recycled for use with future castings.
At this stage, foundry workers will inspect the cleaned castings for defects and clean away excess iron from contact points and the gates where molten iron flowed into the mold. Like the sand, this excess iron is recycled for use in future castings.
After casting, the next step is machining: this is where we produce the Field Skillet's signature smooth cooking surface and lightweight silhouette.
Raw castings straight from the foundry pack a few extra pounds of iron around the cooking surface and side walls—if cast too thin, iron is prone to imperfections. The oldest vintage manufacturers machined and polished every piece by hand, producing truly unique handmade iron. Today, skilled workers use a mechanized version of a similar process to first remove excess material (and weight), then dial in a precise, perfectly level and uniformly thick cooking surface that’s smooth with just a touch of texture.
A machined casting will look like a super-shiny Field Skillets, but it’s still one important step shy of being ready for prime time.
‘Tis the Seasoning
Before they’re ready to ship, Field skillets are seasoned with multiple coats of grapeseed oil. This is the natural coating—no Teflon, no questionable chemicals—that, along with the pan’s smooth texture, produces non-stick cooking performance. At the factory stage, we call this coat “pre-seasoning.”
What is seasoning? We’ve done a deep dive on how cast iron seasoning works, and how to season a skillet at home. At the factory, the principles are the same: When heated, certain oils polymerize, creating an interlocked, durable, and totally food-safe coat that makes your skillet naturally non-stick. Keep cooking, and you’ll add to that coat and make your pan even better with time and use.
Every Field Skillet is stamped with a casting date on the underside of the pan’s smaller helper handle.
We like to think of the casting date as a kind of skillet birthday, written in a YMDD scheme (that’s year-month-day). Let’s use the Field Company’s birthday as an example: March 6, 2016, the day we officially launched our Kickstarter, would be written as 6C06 (6 = 2016; C = March; 06 = 6).
(At least, that’s how they look today. In 2016 and early 2017, we used a slightly different system: The earliest Kickstarter-era skillets were marked with three-digit Julian dates, like “263.” That refers to the 263rd day of the year; in 2016, that was September 19, the day we poured the very first casting of the Field No.8.)
So, take a look at the underside of your skillet’s “helper handle,” find the date code, and discover your skillet’s born-on date. If you’re inclined to throw a birthday celebration for a piece of cast iron cookware, that might be a good morning to break out the bacon.