If you love coin collecting or even just enjoy flipping through your spare change, there’s one coin you definitely don’t want to overlook—the RPM Wheat Penny, specifically the one with the S over S mint mark.
At first glance, it looks like any other old penny, but thanks to a small minting mistake, it has sold for as much as $32,900. So, what makes this little copper coin such a big deal? Let’s look into it.
Meaning
RPM stands for repunched mint mark. Back in the day, mint marks—those little letters that show where a coin was made—were punched into each coin by hand. Sometimes, the punch wasn’t lined up perfectly, and the mint mark ended up being stamped more than once in slightly different spots. That’s how an RPM error happens.
The S/S RPM is a great example. It means the “S” mint mark (for San Francisco) was stamped twice, and the second impression wasn’t quite in the same place as the first. When you look closely, you’ll see what looks like a shadow or a doubled image of the letter “S.” That simple slip-up is now worth thousands to collectors.
Jackpot
The most valuable of these RPM errors is the 1955-S Lincoln Wheat Penny with a clear S over S mint mark. One of these coins, in pristine condition and with a very noticeable double “S,” sold for a whopping 32,900 dollars at auction.
Even if the coin isn’t in perfect shape, a visible RPM can still make it valuable. Lower-grade versions have sold for hundreds or even thousands of dollars, depending on how clear the error is and how well the coin has been preserved.
Detection
Wondering if you’ve got a valuable penny hiding in your collection? Here’s how to spot an S/S RPM Wheat Penny.
Start by checking the date. Look for Wheat Pennies from 1955, 1946, or 1949 with an “S” mint mark just below the year. Then grab a magnifying glass or a coin microscope and take a close look at the mint mark. You’re searching for any sign of doubling or shadowing around the letter “S.”
It might look like a ghost image or an outline behind the main letter. If you see something like that, don’t jump to conclusions, but don’t ignore it either—it might be worth something.
Value
What gives these coins their hefty price tag? It all comes down to rarity and condition. RPM errors were never meant to happen, and only a limited number made it into circulation. That makes them extremely collectible, especially if the mistake is strong and easy to see.
Condition plays a major role too. A coin with no scratches, good color, and a sharp strike will always fetch a higher price than one that’s worn out. But even slightly circulated RPM pennies can still bring in decent money if the error is clear.
Here’s a quick comparison:
| Coin Condition | Estimated Value |
|---|---|
| Mint Condition | $20,000–$32,900 |
| Fine Condition | $1,000–$5,000 |
| Lower Grades | $100–$500 |
Advice
If you think you’ve found an S/S RPM penny, don’t clean it. Cleaning can ruin the surface and kill its value. Instead, use proper tools to examine it closely and take clear photos if needed.
Then, consider sending it to a professional grading service like PCGS or NGC. They can authenticate and grade the coin, which helps prove its value in the market.
So, next time you’re sorting through old coins or buying from a local shop, pay extra attention to those wheat pennies with “S” mint marks. A tiny, barely visible detail could turn one cent into a life-changing windfall. In the world of rare coins, it’s the little things that make the biggest difference.
FAQs
What does RPM mean in coins?
RPM means Repunched Mint Mark—an error where the mint mark is stamped twice.
Which RPM penny sold for $32,900?
The 1955-S Lincoln Wheat Penny with a strong S/S mint mark.
How do I spot an S/S RPM?
Look closely at the ‘S’ for doubling or a shadow effect using a magnifier.
Should I clean my RPM penny?
No. Cleaning can damage the coin and reduce its value.
Where to get an RPM penny checked?
Send it to PCGS or NGC for grading and authentication.
