The Valuable 1918 Walking Liberty Half Dollar Errors: Complete Guide
Five error and variety types regularly command premiums above standard 1918 half dollar values. Below, each is profiled in detail — covering what the error is, how to spot it with magnification, and why collectors pay up for it. Wartime production pressures in 1918 made minting anomalies more common than in quieter production years.
The Repunched Mint Mark error on 1918 half dollars results from the hand-punching method used to place mint marks directly onto working dies before 1989. When an initial punch produced a weak or misaligned impression, mint workers struck the die a second time — occasionally at a different angle or position — leaving a doubled or offset version of the "D" or "S" visible under magnification.
To spot an RPM, examine the reverse at the 8 o'clock position using 5x to 10x magnification. Look specifically for shadowing alongside the primary letter, an extra serif or partial letter impression offset from the main mark, or additional metal appearing as a secondary bump. True RPMs show both images as fully raised metal, distinguishing them from die deterioration doubling which appears flat and mushy.
Collector demand for 1918 RPM examples is driven by the relative rarity of dramatically repunched examples on this series — most are subtle and require sharp magnification to confirm. Strong, dramatic repunchings in uncirculated grades represent some of the most attractive error coins from the 1918 issue for variety specialists working from CONECA or Cherrypickers' Guide listings.
An off-center strike occurs when the coin planchet is not properly centered between the obverse and reverse dies at the moment of impact, causing the full design to appear shifted in one direction. The result is a coin with a crescent-shaped area of completely blank, unstruck metal visible along one edge — and the opposing portion of the design either compressed or partially missing.
Visual identification is immediate — any off-center example is obvious to the naked eye. The critical factor is whether the date remains fully visible: since the date is positioned near the lower edge of the 1918 obverse, 5–15% off-center shifts often preserve it. Dramatic 25–50% examples that still show the full date are the most prized, as they cannot be attributed to a specific year without it. The crescent of blank metal should have a sharply defined edge rather than a gradual fade.
Collector demand peaks when Liberty's walking figure remains largely intact despite the displacement, the unstruck area forms a clean, well-defined arc, and the full 1918 date is legible. More modest 5–10% shifts add meaningful but smaller premiums to base value. Professional authentication is recommended for significant examples before selling.
Clipped planchet errors result from the coin blank (planchet) being improperly cut from the metal strip before striking. The most common type — a curved or "crescent" clip — occurs when the blanking punch overlaps a previously punched hole in the strip, removing a curved segment from the edge. Straight clips occur when the strip is misaligned as it feeds through the blanking machine.
Examination requires looking along the coin's edge where a curved or angled section of metal appears to be physically absent, as opposed to simply worn or damaged. Authentic clipped planchets almost always show the "Blakesley Effect" — a corresponding area of weakness in the design on the rim directly opposite the clip, caused by insufficient metal flow during striking. This diagnostic feature distinguishes genuine clips from post-mint damage that merely looks similar.
Value scales directly with the size and drama of the clip. Small clips (under 10% of the planchet) add modest premiums of $30–$150 to base value. Larger clips removing 15–25% of the planchet — especially those preserving the Blakesley Effect clearly — command $200–$500 or more. The 1918 half dollar's 30.6mm diameter makes dramatic clips highly visible and collectible.
Die crack errors occur when the hardened steel dies used to strike coins develop fractures from the repeated mechanical stress of production. As metal flows into the fractured area during each strike, it creates a thin raised line on every coin struck from that point forward. By 1918, the U.S. Mint was operating at wartime capacity, and production pressures accelerated die wear and cracking across all three mints.
A die crack appears as a thin raised line running across one surface of the coin, traversing part or all of the design. Unlike contact marks or scratches — which are incuse (pressed into the surface) — die cracks are fully raised metal, often with a slight irregularity compared to the surrounding design. A "cud" error represents an advanced stage: when a large fragment of the die breaks away entirely near the rim, it leaves a raised, blob-like area of unstruck metal at the coin's edge, highly distinctive and immediately identifiable.
Minor die cracks crossing uninspiring areas of the design add $25–$75 to base value. More prominent cracks traversing Liberty's figure or the eagle — especially those spanning 30–40% of the coin's surface — command $100–$200 premiums. Full cud errors at the rim, where the blob is large and well-defined, are the most desirable examples and can reach $200–$300 or more depending on position and coin grade.
The 1918-D Missing Designer's Initials variety, catalogued as FS-901 in the Cherrypickers' Guide and recognized by NGC's VarietyPlus program, occurs when the "AW" initials of designer Adolph A. Weinman are absent from the reverse of the coin. Under normal circumstances, Weinman's tiny "AW" monogram appears on the rock outcropping just above the eagle's right claw near the lower right of the reverse. On the FS-901 variety, die polishing or excessive lapping removed these initials before the die was placed in service.
Authentication requires examining the small rock area above the eagle's right claw (lower right reverse) under 10x magnification. On standard 1918-D coins, the "AW" monogram is present as a tiny but legible raised device. On the FS-901 variety, this area is flat or smoothed over — the initials are completely absent rather than merely weakly struck. This distinction is critical, as weakly struck examples are not the same variety and carry no premium.
The FS-901 variety commands enormous premiums precisely because it combines the 1918-D's key date status with a recognized attributed variety designation. The Greysheet value range extends from $34 for worn circulated examples up to $187,000 for gem uncirculated specimens — far exceeding even the regular 1918-D's premium values. Professional authentication by PCGS or NGC is essential before buying or selling any example claimed to be this variety.
