Study Major Error Categories and Diagnostics
4 hoursLearn to distinguish die cracks, cuds, off-center strikes, broadstrikes, and hub doubling from post-mint damage.
Field context
This workflow is part of 4 niche fields
Complete guide for error coin hunting — step-by-step workflow, tools, checklist, and expert tips to get started.
Learn to distinguish die cracks, cuds, off-center strikes, broadstrikes, and hub doubling from post-mint damage.
Order boxed coins from banks, focus on known productive dates, and track search cost per find.
Examine each coin under 10× loupe for rotation, doubling, and strike anomalies; set aside candidates for confirmation.
Verify attributions against Wexler or CONECA listings, then submit valuable finds for attribution or sell raw to variety dealers.
Log roll sources, search dates, error type candidates, and confirmation references for each find.
Apply structured diagnostic criteria to distinguish genuine hub doubling from machine doubling artifacts.
Capture macro photos of suspected errors for online attribution confirmation before slabbing.
Track find rate and cost per error against roll search expenses to evaluate hunting profitability.
Productive series for beginner error hunters.
| Series | Error Type | Search Tip |
|---|---|---|
| 1955 doubled die cent | Hub doubling | Check LIBERTY and date |
| Off-center cents | Strike error | Any date — value scales with off-center % |
| Nickels 1938– | Die cracks, cuds | Jefferson collar errors rare but exist |
| State quarters | Die breaks | Check extra leaves and die chips |
Flat shelf-like doubling on cent letters is machine doubling — worth face value only.
Wrong planchet and clipped planchet errors show on scale before loupe confirms.
Ordering excessive boxes without returning coins burns bank relationships — search ethically.