Derby City Coin Club 

Louisville, Kentucky Numismatic Interest Group

Clipped Coin Diagnostics

By:  Kenneth Jones

Most collectors of Numismatic Errors are aware of the Blakesley effect on clipped coins. This shows as a weakness in the design elements directly opposite of the clipped area. This is because during the upsetting stage that turns a blank into a planchet, (or type one to type two planchet), the missing clipped area causes the similar sized area on the opposite side to not be upset. The resulting flat spot in this area provides less material to fill in the voids in the die when the coin is struck and this gives you the design weakness.

The Blakesley effect is a good diagnostic tool, but as with almost everything, there are exceptions. I have seen a straight “clip” Jefferson Silver composition War Nickel that is an exception. The design elements at the edge of the missing area exhibited the usual fading of the details caused by the metal flowing between the dies instead of into the design voids. The opposite side from the clip was completely normal. This piece shows the improper alloy mix problem common to these coins. The “clipped” edge was not machine sheared, but had a layered, almost ragged, appearance. It appears that this coin started as a complete planchet and after the upsetting process part of the planchet broke off due to the alloy mix problem and was then struck. This was an unusual incomplete planchet coin.

 As just mentioned, any clipped coin should exhibit design weakness near the clip area. The coin rim will taper into the clip and the design lettering will usually have a stretched, thin appearance. The coin metal flowing under pressure will try to take the easiest path and filling the void left by the clip is usually it. Be very wary of clipped coin that show crisp clear design elements right up to the clipped edge!

 I have found another clip trait that I would propose to be a diagnostic for curved clips on clad composition coins. This diagnostic concerns the appearance of the curved clipped edge in relation to the non-clipped edge of the coin.

 The edge of any Copper Nickel clad coin will show three distinct layers. The outer Nickel layers and the inner copper core layer. Looking at the edge of the coin, one of the nickel layers always appears thicker than the opposite nickel layer. The relation of the obverse / reverse of the coin have no bearing on this apparent thickness. Actually the layers are the same thickness. I will explain this effect shortly.

 On the curved clipped edge of the coin, this layering effect will be reversed. The nickel layer that appears thicker will be opposite of the non-clipped edge. This is true for un-struck clipped planchets and blanks as well.

 The cause of this appearance is the punching process. Here is where it gets technical and I will attempt to explain the effect.

 The punch machine is a gang punch. It stamps out several rows of blanks and then the metal strip advances past the previously punched area and the process repeats. When the metal strip does not advance correctly and the previously punched hole overlaps the punch, the next machine cycle results in curved clip blanks being produced.

 For the sake of simplicity, let’s consider a single punch and two machine cycles.

 The punch machine RAM is the part that comes down on the metal strip and pushes the metal through the bottom of the punch machine, called the FORM.  The line at witch the blank separates from the metal strip is called the SHEAR LINE. Now as the RAM comes into contact with our tri-layered metal strip, the top layer of nickel is held by the RAM and pressed down. The nickel layer under the RAM at the SHEAR LINE separates smoothly. The nickel layer of the metal strip at the SHEAR LINE not being held by the RAM pulls (stretches) downward during this time. On the bottom side of our strip, the RAM is pushing the bottom layer of nickel through the FORM. This layer at the SHEAR LINE also pulls (stretches) upward. The bottom layer of nickel at the SHEAR LINE held in place by the form separates smoothly.

So the nickel layer being stretched is the top of the metal strip left after the punching operation and the bottom of the punched out blank.

 When the strip does not advance correctly and the previously punched hole overlaps the RAM / FORM area, the next cycle the metals will pull just as before. What you are looking at when you look at the curved clip edge of the coin is what should have been the punched edge of the left over metal strip. The reversal of the nickel layer pulling (stretching) during the punching process is the cause of the clad layers apparent thickness flip-flopping on a curved clip clad coin, blank, or planchet.

As I said earlier, there is always an exception! If a previously punched blank were to re-enter the RAM /FORM area and go through the cycle again, you would have a fifty % chance that this effect would not appear. This might sound far-fetched but it would be possible. I mention it as a possibility because I have a Partial Punch clad blank that was punched out then hit by adjacent punches later

 Straight and Ragged clip pieces are the result of entirely different circumstance and this effect, if present, would be from another cause. Possibly from when the metal strip was sheared to length.

 The last diagnostic that I can recommend is experience. Go to coin shows and ask to see any clip coins the dealers have. After awhile you will develop an “Eye” for clips. I have seen, clips for sell that I knew were faked by the picture, coins in dealers cases at major shows priced in the four figure range that were bogus. But I got to tell You, I just love picking a clipped Buffalo nickel out of someone junk box!