🔍 Strike Parameters & Date Attributions
PCGS FB & NGC FSB🔬 Microscopic Reverse Fasces Band Reticle
Central Band High-Magnification📋 Strike Forensic Analysis & Valuation
Loading strike diagnostics...
Numismatic Strike Anatomy: The Mercury Dime Fasces & Full Split Bands
The Winged Liberty Head dime, affectionately called the "Mercury Dime," was designed by prominent American sculptor Adolph Alexander Weinman and minted from 1916 through 1945. The obverse depicts Liberty wearing a Phrygian winged cap, while the reverse features a Roman fasces (a bundle of birch rods bound around a battle-axe) entwined with an olive branch of peace.
1. The Mechanical Anatomy of the Fasces Bands
The birch rods are held together by three pairs of horizontal cross-straps: two at the top, two at the center, and two at the bottom, bound with diagonal crisscross cords. In numismatic grading, the central pair of horizontal straps is the definitive testing ground for coining pressure:
| Band Inspection Zone | Strike Requirement | Common Failure Mode | Disqualification Factor |
|---|---|---|---|
| Central Horizontal Bands | 100% full separation with a continuous, deep, dark recess groove | Worn master hubs cause dies to lack central cavity depth, leaving a solid flat bridge | Any flatness, bridging, or unbroken metal flow across the center |
| Contour Rounding | Both the upper and lower bands must display convex, rounded relief | Insufficient press tonnage leaves bands squared-off or plateaued | Flat-topped bands with shallow, indistinct separation |
| Surface Preservation | Uninterrupted horizontal groove free of post-strike mechanical gouges | Planchets bumping in hopper or bag creates reed mark across the split | Any contact mark that shears or closes the dividing channel |
\(\text{Value}_{\text{FB}} = \text{Value}_{\text{Non-FB}} \cdot M_{\text{Strike Rarity}}\)
Examples of Strike Rarity Multipliers at MS65 Grade:
• 1941-P: \$32 Non-FB → \$65 FB (2.0x Multiplier - Common Date)
• 1919-D: \$450 Non-FB → \$3,800 FB (8.4x Multiplier - Branch Mint Scarcity)
• 1945-P: \$30 Non-FB → \$14,500 FB (483x Multiplier! - The Holy Grail Strike Rarity)
2. Why the 1945 Philadelphia Dime is the Legendary Strike Holy Grail
In 1945, the Philadelphia Mint operated around the clock to meet massive economic demand, coining over 159 million Mercury dimes. Because steel was rationed for the war effort, the engraving department continued using exhausted, tired master dies long after their relief features had flattened out. On the master hubs, the central fasces groove had completely vanished.
As a result, more than 99.99% of all surviving 1945 Philadelphia dimes exhibit a flat, solid slab of metal where the center bands should be. Only a handful of working dies—believed to have been cut from a fresh master hub early in the year—possessed the full split groove. When discovered in Gem MS65 or higher, the coin commands fierce bidding wars at major auctions, routinely realizing upwards of \$15,000 to \$30,000.
Real-World Collector & Cherrypicking Case Studies
Case 1: Cherrypicking a 1945-P Full Bands at a Local Coin Show
At a small regional bourse, an astute variety hunter examined a dealer's bid box of raw, uncertified Mercury dimes priced at \$15 each. Spotting a blazing white 1945 dime with intense cartwheel luster, he inspected the reverse under a 16x Hastings triplet loupe: both central horizontal bands were fully rounded with an unmistakable, pitch-black split shadow from edge to edge. Submitted to PCGS, it received a grade of MS65FB, subsequently realizing \$14,100 through Stack's Bowers.
Case 2: The Heartbreak of the Bag-Marked 1916-D
A collector purchased a raw 1916-D Mercury Dime for \$8,000, hoping to achieve an MS63FB certification (worth \$24,000). The bands were struck sharply with deep relief; however, a microscopic reed mark from the edge of another coin had grazed directly across the center split groove, flattening a 0.2mm bridge of metal. PCGS assigned the grade MS63 without the FB designation, capping the value at \$9,500.
Case 3: Branch Mint Spacing on the 1926-S
With an original mintage of only 1,520,000, the 1926-S is a key date in the series. San Francisco press operators deliberately loosened press tension to prolong die life during the 1920s. While common in Fine to Very Fine, locating a 1926-S with Full Split Bands in Mint State is exceedingly difficult: an MS65 non-FB trades for around \$1,200, whereas an authentic MS65FB commands over \$9,000.
Diagnostic Pitfalls & Disqualification Red Flags
- Confusing the Top or Bottom Bands with the Center: The Full Bands designation requires the central horizontal pair to be split. Occasionally, a coin will display split top and bottom straps but a flat center strap; such coins do NOT qualify for FB.
- Tooling and Engraver Alterations: Unscrupulous individuals have been caught using micro-chisels or dental engraving tools to manually carve a groove into a flat 1945 dime. Under 30x stereo magnification, altered grooves exhibit jagged tool marks, displaced metal burrs, and broken mint luster.
- Friction on AU58 Coins: Never mistake an AU58 coin with flat bands for a weakly struck Mint State coin. Check the high points of Liberty's hair curls above the ear and the cheekbone for friction wear and luster interruption.
Frequently Asked Questions (FAQ)
Explore More Professional Numismatic & Coin Tools
Continue your coin collecting research with our suite of specialized numismatic calculators, grading engines, and variety attribution suites: