If you enjoy coin collecting or just have a habit of checking your pocket change, here’s one coin you should definitely know about—the RPM Wheat Penny.
It may look like any regular penny at first glance, but a small minting mistake known as a repunched mint mark (RPM) has turned some of these coins into rare treasures worth up to $32,900.
Meaning
RPM stands for Repunched Mint Mark. It’s a type of minting error that happens when the mint mark on a coin—like the letter “S” for the San Francisco Mint—is punched into the die more than once but in slightly different positions.
Instead of removing the first incorrect mark, the mint worker accidentally strikes the mint mark again, slightly off-target. This results in what collectors call an “S over S” or “S/S” mark. You can often spot this with the help of a magnifying glass or coin microscope.
Example
The most valuable RPM coin is the 1955-S Lincoln Wheat Penny with the S/S repunched mint mark. In perfect condition, one of these coins sold at auction for an impressive $32,900.
Here’s a quick breakdown of what these coins might fetch:
| Coin Year | Mint Mark | Condition | Value Range |
|---|---|---|---|
| 1955-S | S/S RPM | Mint State (MS) | Up to $32,900 |
| 1955-S | S/S RPM | Average Condition | $100 – $1,000+ |
| 1946-S, 1949-S | S/S RPM | Varies | $20 – $1,000 |
Even lower-grade versions can still be worth hundreds of dollars if the RPM is clear and easy to spot.
Detection
Want to check your coins? Here’s how to spot an RPM penny:
- Date: Focus on Lincoln Wheat Pennies from 1955, 1946, and 1949
- Mint Mark: Look for the “S” just below the date
- Doubling: A clear double or shadow-like impression around the “S”
- Tools: Use a coin microscope or a strong magnifying glass to inspect the mint mark
If it looks like the “S” was stamped twice, slightly misaligned, you may have a valuable RPM penny.
Value
Why are these pennies worth so much more than face value? It comes down to three things:
- Scarcity: These errors happened rarely and unintentionally
- Condition: Coins in higher grades fetch much higher prices
- Collector Demand: Many coin collectors specifically look for RPM errors
The clearer the doubling and the better the coin’s overall condition, the higher the value. Coins graded by professional services like PCGS or NGC often sell for much more at auctions.
Advice
If you think you’ve found a possible RPM coin, don’t clean it. Cleaning can scratch the surface and destroy its collector value. Instead:
- Inspect it using proper tools
- Compare it with known RPM examples online
- Send it to a coin grading service for authentication
The RPM Wheat Penny is proof that even small mint errors can create big value. What was once just a small mistake at the mint is now a prized find in the world of coin collectors.
Whether you’re a serious hobbyist or just curious, keep your eyes open. One small detail could turn an ordinary penny into an extraordinary payday.
FAQs
What does RPM stand for?
It means Repunched Mint Mark, a type of minting error.
Which RPM penny is most valuable?
The 1955-S RPM penny, worth up to $32,900.
How do I spot an S/S RPM?
Look for a shadow or double ‘S’ under the date with a magnifier.
Is every RPM penny valuable?
Not all are extremely valuable, but clear ones in good condition are.
Should I clean my RPM coin?
No, cleaning lowers its value. Keep it as is.
