Clipped Planchet Errors: Types, Authentication, and Value
Clipped planchet errors occur when the blanking press creates an incomplete coin blank — missing a curved, straight, or irregular portion of its edge. The resulting coin shows a distinctive area where metal is absent, and genuine clips carry a telltale authentication marker: the Blakesley effect on the opposite rim.
What This Means
During coin blank production, circular blanks are punched from a long metal strip. If the strip doesn't advance properly, the next punch overlaps the previous hole, cutting into it. The resulting blank has a bite-shaped clip where it overlapped. Straight clips occur when blanks are punched too close to the edge of the strip.
What to Look For
- Curved clip — crescent-shaped missing portion matching a previous punch hole
- Straight clip — flat missing edge from strip edge overlap
- The Blakesley effect — weak or missing rim directly opposite the clip
- Metal flow distortion in the design near the clipped area
- Smooth edge at the clip — no tool marks or roughness
- Multiple clips — two or more clips on the same coin are scarcer
Common Mistakes to Avoid
- Not checking for the Blakesley effect — the most important authentication feature
- Confusing plier damage with genuine clips
- Assuming all edge damage is a clip
- Not examining the edge smoothness at the clip area
- Overlooking small clips that are easy to miss without careful examination
What Affects Value
Clip values depend on the clip size (larger clips are scarcer), type (straight and multiple clips carry higher premiums), denomination, and condition. The presence of a clear Blakesley effect adds authenticity confidence.
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Scan NowFrequently Asked Questions
What is the Blakesley effect?
The Blakesley effect is a weak or flat area on the rim directly opposite a clip. It occurs because the incomplete blank couldn't flow properly during the rim-raising (upsetting) process. It is the primary authentication marker for genuine clipped planchets.
How do I tell a real clip from damage?
Check for the Blakesley effect (weak rim opposite the clip), smooth edge at the clip area (no tool marks), and metal flow distortion in the design near the clip. Post-mint damage lacks these features.
Are small clips worth anything?
Small clips carry smaller premiums than large ones. However, even small clips on less common denominations or with unusual characteristics can be collectible. Large clips (25%+ of the coin missing) are significantly more valuable.
Can clips appear on any denomination?
Yes, clipped planchets occur on all denominations since all coin blanks are punched from metal strips using the same basic process.