Coin Pinger
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Silver coin guide
British Half Crown (pre-1920) — ping test & specs
The sterling half crown (1816 standard, struck to 1919) is 14.14 g of .925 silver at 32.31 mm. Sterling's density sits almost exactly on our coin-silver constants — a clean reference.
Opens the free tester with this coin preselected — audio never leaves your device.
Official specifications
| Weight | 14.138 g |
| Diameter | 32.31 mm |
| Composition | .925 sterling silver |
Source: The Royal Mint. Coin Pinger checks measured weight and diameter against these values.
Expected resonance range
High confidence*| Mode | Expected ring | Recommended variance |
|---|---|---|
| c0d2 | 3.94–4.93 kHz | ±11.1% |
| c0d3 | 9.16–11.35 kHz | ±10.7% |
| c0d4 | 16.01–19.84 kHz | ±10.7% |
A genuine British Half Crown (pre-1920) rings within these ranges at its c0d2/c0d3/c0d4 vibration modes, fixed by its size and metal. The recommended variance is how far a genuine specimen's ring can sit from each center — built up in quadrature from real manufacturing tolerance and temperature (under 1%), phone-mic capture reproducibility (≈4%), an extra allowance on the fundamental for minting-asymmetry splitting, and a per-metal model-uncertainty term (largest for .9999 gold, whose modulus is least certain). This coin's band is widened further because circulated 90%-silver classics lose mass and edge crispness with wear, spreading their ring. The higher modes also carry a small thick-plate centre correction, since a real coin is not infinitely thin. The high-confidence tag reflects how well-established this metal's constants are: Computed from well-established silver elastic constants and cross-checked against same-size sibling coins. These are guidance bands, not exact values — see the methodology for the exact formula, or calibrate your own coin in the app for a specimen-exact reference and tighten each peak per coin.
* These are computed guidance ranges. Certain your British Half Crown (pre-1920) is genuine but it won't match? Send us its ring — we'll dig in and improve the reference.
🎙 Submit sample pingsHow to ping test a British Half Crown (pre-1920)
- Hold — grip the coin by its center (a nodal point) in a coin ping-test holder so the rim rings freely; a fingertip at the center is a last resort.
- Tap — strike the edge with a striker near the microphone.
- Read the verdict — MATCH or NO MATCH against the peaks above, plus weight and size checks.
British Half Crown (pre-1920) — frequently asked
How much does a British Half Crown (pre-1920) weigh?
The official specification is 14.138 g in .925 sterling silver (source: The Royal Mint). Coin Pinger's weight check allows ±0.3 g by default. Circulated specimens lose a little mass to wear, so weigh toward the low side of that window.
What size is a British Half Crown (pre-1920)?
32.31 mm in diameter, per The Royal Mint. Note the average disc thickness is less than the rim caliper reading — the raised rim and relief concentrate metal at the edge.
What frequency does a genuine British Half Crown (pre-1920) ring at?
Its fundamental (c0d2) vibration mode is computed to ring in the 3.94–4.93 kHz range, with higher modes near 9.16–11.35 kHz and 16.01–19.84 kHz. These are first-principles physics computations from the coin's published mass, diameter, and metal — not measurements of sample coins.
Why does my genuine British Half Crown (pre-1920) ring slightly off the listed frequencies?
Wear is the biggest factor for the British Half Crown (pre-1920): circulated 90%-silver classics lose mass and edge crispness, which spreads the ring across specimens. On top of that, phone-mic capture moves a genuine peak a few percent tap-to-tap (strike point, how you hold it, the mic itself). That's why this reference band is wider than a modern bullion coin's.
Does ping testing damage a British Half Crown (pre-1920)?
No — the test needs only a light tap on the edge with a non-marring striker (a wooden pencil or plastic stylus works well), far gentler than normal handling. Hold the coin at its center so the rim can ring freely.