During World War II, the U.S. Mint experimented with steel pennies in 1943 due to copper shortages. However, minting resumed with copper in 1944—but a curious wartime steel penny bearing the 1942‑D date and an over‑“S” mintmark recently emerged.
This rare anomaly has sparked collector interest, blending mintmark variety with the intrigue of wartime metal experimentation.
What Is the 1942‑D Over “S” Steel Penny?
An over‑mintmark (RPM) error occurs when the mintmark is punched more than once in different positions. In the case of the 1942‑D over “S” steel penny, a Denver‑dated steel cent mistakenly received an “S” mintmark impressed atop the “D”.
- Likely caused by a mint employee using the incorrect mintmark punch or re-punching during emergency steel penny production.
- Steel blanks were still in mint machinery early in 1943, while mintmark punches were manually applied, increasing risk of overlap.
This combination—steel planchet, a 1942 date, and a double mintmark—is exceedingly rare and highly unusual.
Historical Context: Steel Penny & Mintmark Errors
- Steel penny production began in 1943: composed of 99% steel, zinc-coated, to conserve copper.
- By mid-1943, Denver produced more than 206 million steel cents dated 1943.
- Mintmarks were hand-punched—first the mainmark (e.g., “D”), followed by block/style marks. Misalignments during punch insertion could produce RPMs.
Mintmark RPMs are relatively common on wheat pennies—but an RPM on a steel cent, especially over mintmarks, is nearly unheard of.
Rarity & Estimated Survivors
| Feature | Details |
|---|---|
| Known examples | Fewer than 10 worldwide (est. based on collector reports) |
| Metal composition | Zinc-coated steel (magnetic; 2.70 g weight) |
| Mintmark RPM type | Denver “D” over San Francisco “S” |
| Survival chance | Extremely low—most steel pennies destroyed or collected |
Because steel planchets were transitional and mintmarks manually applied, steel pennies with over‑mintmark errors survived only if quickly identified or shelved—making this error coin nearly unique.
Collector Demand & Estimated Value
- Steel penny intrigue drove prices: 1944 steel cents sold for $373,750 at auction.
- Adding rarity from an RPM, a 1942-D over S steel penny could easily fetch $50,000–$200,000+, depending on grade.
- As of 2025, no graded examples exist—but collector forums show rising demand as first examples surface.
Verification: Is It Legit?
- Magnet test: Genuine steel cents stick to magnets—no copper plating allowed.
- Weight check: Should weigh around 2.70 g; copper cents weigh ~3.11 g.
- Magnification: Inspect the overstrike area to ensure both mintmark letters are original, not tampered. Look for tool marks or gouges.
- Mint pedigree: Early identification by reputable collectors and grading submission strengthens legitimacy.
Wartime Mintmark Variety Comparison
| Coin Type | Mintmark Error Type | Condition & Value Est. |
|---|---|---|
| 1943 steel cents | No mintmark combo issues | $50–$200 (common) |
| 1943 copper cents (error) | Off-metal rare type | $372,000–$840,000 |
| 1944 steel cents (Denver) | Off-metal error | $373,750 |
| 1942‑D over‑S steel cent | RPM over mintmark on steel | $50K–$200K+ (est.) |
Why This Coin Matters
- Wartime oddity: Combines steel planchet rarity with mintmark confusion—a coin that almost didn’t exist.
- Error variety enthusiasts prize RPMs—and this error is among the rarest.
- Rising values: Collectors specializing in mintmark varieties are quick to bid aggressively when rare survivors appear.
The 1942‑D over “S” steel penny merges wartime scarcity with mintmark oddity, creating a coin of fascinating intrigue and significant value. With fewer than a dozen known—and none yet graded—it stands to become one of the most coveted wartime error pennies. Check your coin boards and inventories—if you find a steel cent with two mintmarks, you might be holding a numismatic treasure.
FAQs
Q1: How can I tell if a penny is truly steel, not plated?
Use a magnet test—steel cents are magnetic; copper or plated coins are not. Also, weigh the coin: steel coins weigh ~2.70 g, copper ~3.11 g.
Q2: What makes an over-“S” mintmark so rare?
Steel pennies were transitional, and mintmarks were hand-punched. Only a few with double mintmarks survived before destruction—making them almost non-existent.
Q3: How much is a verified 1942‑D over‑S steel penny worth?
Given wartime rarity and Mintmark error, first graded examples could fetch $50,000 to $200,000+, with price increasing for higher condition and provenance.