How to Spot Valuable Cast Iron at Thrift Stores: Griswold, Wagner and Unmarked Pans

Quick answer: Flip the pan over and read the bottom. Marked Griswold (especially the slant and large block logos) and early Wagner Ware marked "Sidney -O-" are the names collectors pay up for. Some unmarked pans are valuable too, like older Lodge skillets with one or three notches in the heat ring. Condition matters just as much as the maker, so check for cracks, warping and pitting before you buy.

Cast iron is one of the best thrift store finds out there. It's heavy, it's often filthy, and a lot of people walk right past it. But a crusty old skillet can turn out to be a pan collectors actively hunt for. Here's how to tell the difference in about a minute, right there in the aisle.

Start with the bottom of the pan

Almost everything you need to know is on the underside. Turn the pan over, hold the handle toward you, and look for four things:

• A maker's logo or name. Griswold, Wagner, Lodge and others often cast their name into the bottom.
• A heat ring. This is a raised ring around the outer edge of the bottom. Older pans often have one. Many later pans have a smooth bottom.
• Numbers. Most pans have a size number. Some also have a pattern number, which is a separate catalog number and helps a lot with identification.
• "Made in USA." This mark usually points to later production, roughly the mid-1960s on, depending on the maker.

Take a clear photo of the whole bottom before you clean anything. The exact wording, layout and spacing of the marks are what collectors use to date a pan, and small details matter.

How to identify Griswold cast iron

Griswold made cast iron in Erie, Pennsylvania, from the late 1800s until the Erie plant closed in 1957. It's the name most collectors want first. The logo is a cross inside a double circle with "GRISWOLD" across it, and the logo style is your best clue to age:

• Slant logo (about 1906 to 1929): The word GRISWOLD is in italic lettering. Smooth-bottom pans with the slant logo are scarce and highly collectible.
• Large block logo (about 1920 to 1940): Big, bold block letters, usually with "CAST IRON SKILLET" and "ERIE, PA, U.S.A." This is the classic Griswold look and a favorite with collectors.
• Small block logo (about 1939 to 1957): A smaller, lighter logo with "ERIE, PA." These are still good pans and still sell, but usually for less than the earlier marks.

After 1957 the Griswold name went to other owners and was eventually dropped in the early 1970s. Pans marked Griswold without "ERIE, PA." come from that later period and are generally not what collectors are chasing.

Griswold also made unmarked and store-brand lines, including "Iron Mountain" skillets with italic size numbers and a four-digit pattern number. These have collector interest of their own, so an unmarked pan with Griswold-style features is worth a closer look.

How to identify Wagner cast iron

Wagner was based in Sidney, Ohio, and its pans are often marked "Sidney -O-." Wagner took over the Griswold brand in the late 1950s, and Wagner cast iron kept going until the foundry closed in 1999. That long run means you'll see a lot of Wagner at thrift stores, and the age makes a big difference.

• Heat-ring "Wagner Ware Sidney -O-" (roughly 1920s to mid-1930s): Earlier and more sought after.
• Stylized "Wagner Ware" on a smooth bottom (roughly 1935 to 1959): Still collectible when the condition is strong.
• "Made in USA" pans: Generally post-1960s. These are often great pans to cook with but carry less collector value.
• "Wagner's 1891 Original": Don't let the date fool you. This line launched in 1987. It is not an 1891 pan.

Also watch for Magnalite. It carries the Wagner name but it's cast aluminum, not cast iron.

Unmarked cast iron: don't skip it

Plenty of good vintage pans have no name at all. Many were made by big foundries and sold under store brands. Most unmarked pans are worth more as cookware than as collectibles, but a few types do have collector value.

Older Lodge skillets

Lodge traces its roots to the Blacklock Foundry, started in 1896 in South Pittsburg, Tennessee. For decades, many Lodge pans weren't marked with the name. The notches in the heat ring are the giveaway:

• One notch at 12 o'clock: Points to roughly the 1930s.
• Three notches at 9, 12 and 3 o'clock: Points to roughly the 1940s through 1987.

Both of these notched Lodge skillets have collector interest, so a "no-name" pan with notches is a find.

Birmingham Stove & Range and others

Birmingham Stove & Range skillets usually have an unbroken heat ring set in from the edge, with a large size number at 6 o'clock. They're solid, well-made pans that tend to sell for less than marked brands, which makes them great buys if you just want something to cook with.

What drives cast iron value

The maker gets a buyer interested. Condition decides the price. Before you pay, run through these checks:

• Cracks: Hairline cracks usually run down the sidewall from the rim. They're hard to see through old seasoning, so tilt the pan under good light. A cracked pan loses most of its collector value. The "ring like a bell" tap test isn't reliable, so don't count on it.
• Warping: Set the pan on a flat surface and press on the rim. If it rocks or spins, it's warped. Collectors call these "spinners," and they're worth much less.
• Pitting: Small eroded spots from rust or years over a fire. Pitting can't be undone and it lowers value.
• Fire damage: A dull, scaly, reddish surface can mean the pan was burned in a fire. Seasoning often won't stick to it well.
• Repairs: Look for welds on handles or filler on the surface.

Size and rarity matter too. Common sizes turn up all the time. Unusual sizes, odd pieces and scarce logos are what push a pan into serious money.

Also watch out for reproductions. Fake "Griswold" pieces, often small items like toy skillets or cornbread pans, tend to have a grainy finish and blurry lettering. A sharp, crisp logo is a good sign.

How to check what your cast iron is worth

Ignore asking prices. Anyone can list a rusty skillet for a big number. What matters is what pans like yours have actually sold for.

1. Identify the exact pan. Note the maker, logo style, size number, pattern number and whether it has a heat ring.
2. Search sold listings. On eBay, search the maker, logo and size, then filter to sold or completed items.
3. Match the condition. Compare your pan to sold pans in similar shape. A clean, flat, crack-free pan and a warped one are not the same item.
4. Look at several sales. One high sale can be a fluke. Look for a range.

If you'd rather not dig through listings in the store, you can snap a photo with Moe to identify the item and see its current market value before you decide to buy.

Where to sell vintage cast iron

• eBay: The biggest audience of cast iron collectors, and the easiest place to see sold prices. Good for marked Griswold and early Wagner.
• Facebook Marketplace: Cast iron is heavy and pricey to ship, so selling locally can make sense for everyday user pans.
• Etsy: A good fit for clean, restored vintage pieces with nice photos.
• Cast iron collector groups and shows: Collector communities know exactly what they're looking at, which helps with rare pieces.

Listing on more than one marketplace gets your pan in front of more buyers. Moe can cross-list to several marketplaces and keep buyer messages in one place, so you're not juggling apps.

Tips for buying and selling

• Don't burn off the crud. Burning off old crud in a fire or a self-cleaning oven can warp or ruin a pan. Collectors use lye baths or electrolysis instead.
• Skip sandblasting and grinding. Both permanently change the original surface, and collectors notice.
• Photograph everything. Shoot the bottom, the cooking surface, the rim and the handle in natural light. Flash hides detail.
• Disclose flaws clearly. "Great shape for its age" tells a buyer nothing. Say whether it sits flat, and point out any pitting.
• Price for the market, not the memories. Grandma's skillet means a lot to you, but buyers pay for maker and condition.

Cast iron often shows up next to other kitchen finds worth grabbing. If you're already in the housewares aisle, see our guide to which Pyrex patterns are worth money, and our list of what to look for at thrift stores.

Frequently asked questions

How can you tell if cast iron is valuable?

Check the bottom for a maker's mark. Griswold with an "ERIE, PA." mark, especially the slant or large block logo, and early Wagner Ware marked "Sidney -O-" are the most collected. Then check condition. Cracks, warping and pitting cut value a lot.

Is unmarked cast iron worth anything?

Usually more as cookware than as a collectible, but there are exceptions. Older Lodge skillets with one or three notches in the heat ring and certain unmarked Griswold lines have collector interest.

How do I know if my Griswold is old?

Look at the logo. Slant logos date to about 1906 to 1929, large block logos to about 1920 to 1940, and small block logos to about 1939 to 1957. Pans without "ERIE, PA." were made after the Erie plant closed in 1957.

Is Wagner cast iron as good as Griswold?

Older Wagner is very well made and many cooks love it. Collectors generally pay more for Griswold, but early Wagner Ware marked "Sidney -O-" is also sought after.

How do I check if a cast iron skillet is warped?

Set it on a flat, hard surface and press down on the rim. If it rocks or spins, it's warped. You can also lay a metal straightedge across the cooking surface to check for a hump.

Should I clean a rusty cast iron pan before selling it?

A gentle cleaning can help it sell, but avoid fire, self-cleaning ovens, sandblasting and grinders. Many sellers photograph the pan before cleaning too, since collectors like to see the original marks clearly.