The Nickel
5 cents
Since 1866, the U.S. nickel has been 75% copper and 25% nickel, mixed so evenly at the atomic level that it is the same metal from surface to center. That matters: coin machines identify a nickel partly by how its metal reacts to a changing magnetic field, so any new recipe has to match it closely. The only big exception was World War II, when nickel was needed for the war and the coin briefly contained silver. In 2026, Congress passed the Common Cents Act, which lets Treasury test a cheaper nickel with a zinc core and a nickel outer layer.
Composition & Tolerances
| Variant | Standard Cupronickel Nickel 1866–1942, 1946–today | Wartime Silver War Nickel Oct 1942–1945 | Counterfeit Henning Counterfeit Fake dated 1944 | Proposed Zinc-Core Nickel Common Cents Act, 2026‡ |
|---|---|---|---|---|
| Copper | 75% | 56% | 79% | — (replaced by zinc) |
| Nickel | 25% | 0% | 20%§ | Outer layer, % set by Treasury‡ |
| Silver | — | 35% | — | — |
| Silver content | — | 0.0563 troy oz | — | — |
| Manganese | — | 9% | — | — |
| Zinc | — | — | — | Inner core, % set by Treasury‡ |
| Structure | Solid alloy throughout | Solid alloy throughout | Solid alloy throughout | Nickel skin over zinc core |
| Target weight | 5.000 g | 5.00 g | Not published | 4–6 g range‡ |
| Weight tolerance | ±0.194 g* (4.806–5.194 g) | Reported same as standard† | None (made to no spec) | Not yet set |
| Composition tolerance | Not published | Not published | None | Not yet set |
| Diameter | 21.21 mm | 21.21 mm (same as standard) | Not published | Not yet set |
| Thickness | 1.95 mm | Not confirmed | Not published | Not yet set |
| Edge | Plain | Plain | Plain (copied) | Not yet set |
| Magnetic? | No | No | No (copper-nickel alloy) | Possibly (pure nickel skin) |
| Specific gravity | 8.92¶ | 9.25¶ | Not published | Lower (zinc ≈7.2¶) |
| Conductivity | 5.5% of copper (IACS) | Not published | Not published | Zinc 27%, nickel 22% (pure metals) |
| How to spot it | Any date outside the war years | Large P, D or S mint mark above Monticello's dome | 1944 date with no mint mark above the dome | Not yet issued |
Footnotes
Cupronickel Nickel: * Commonly cited collector figure; federal law leaves minor-coin tolerances to the Treasury Secretary. ¶ Specific gravity values are commonly cited collector figures; the zinc value comes from the zinc cent. Conductivity is a percent of pure copper (IACS).
Silver War Nickel: † Reported by collectors; not confirmed in Mint records.
Henning Counterfeit: § PCGS lists 79% copper and 20% nickel; the remaining ~1% is not specified.
Zinc-Core Nickel: ‡ The Common Cents Act lets Treasury set the exact recipe after testing shows it lowers cost and, as far as practical, has minimal impact on coin machines.
Sources
- Coinage Act of May 16, 1866
- Act of March 27, 1942 (wartime nickel alloy)
- Common Cents Act, S. 1525 bill text: https://www.lankford.senate.gov/wp-content/uploads/2026/08/Common-Cents-Act-1.pdf
- PCGS CoinFacts, 1944-P 5C: https://www.pcgs.com/setregistry/mycoinfacts/1944-p-5c/4033352
- CoinWeek, Jefferson War Nickel: https://coinweek.com/war-nickel-how-to-identify-these-valuable-nickels
- U.S. Mint Biennial Reports to Congress (2014, 2020, 2022)
- CoinTalk, Coin Specific Gravity (collector chart): https://www.cointalk.com/goto/post?id=2132275
- Blue Sea Systems, Electrical Conductivity of Materials: https://www.bluesea.com/support/articles/Materials/108/Electrical_Conductivity_of_Materials
- USPTO, Coinage cladding alloy patent (C71300 conductivity): https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/10513768