Reeding Present Only In (Apparent) Clip?

I am sure that the "Blakesley Effect" was written up in Coin World's Collectors Clearinghouse in the 1970's, either by Jim Johnson before he retired in 1974, by Ed Fleischmann before he left to go work for ANACS in 1976, or by myself before I left in 1978.

The Blakesley Effect is a multi-step process. It must be preceded by the creation of a flat blank with some metal missing along the edge in one or more places. This void (or voids) is typically caused by the blanking press creating overlapping holes (a standard clip), or by the blanking press overlapping a straight edge on the strip (a straight clip), or by the blanking press overlapping a rough void in the strip (a ragged clip).

As the incomplete blank is passed through the upsetting mill, the proto rim is formed by the opposing pressures where the diameter is complete from one side to the other and not formed where the diameter is incomplete. This is the Blakesley Effect as seen on an unstruck planchet. In the case where the voids are very minor, partial upsetting may occur.

During the normal upsetting process the diameter of the planchet is reduced slightly. I have measured Type one Blanks and Type Two Planchets and the difference is very minor, but measurable. Where the non-void side of the blank is not squeezed inwards to form the proto rim, the non-moved metal may appear as a very minor "bulge" since the metal on either side of it was moved inwards, but I would not expect it to interfere with the planchet feeding into the collar or survive the strike.

During the strike the force of the press will attempt, and typically fail, to reshape the non-upset area of the planchet, the Blakesley Effect, into the rims on the dies. The amount of reshaping that is accomplished depends on the metal involved, the relief of the dies and the pressure setting on the press. The result is typically a coin that shows a Blakesley Effect that survived from the planchet preparation process.

TD

 

Log in or Sign up to hide this ad.

Jaelus, posted: "It doesn't contradict it at all. You're saying the lack of metal in that part of the planchet, when struck, is the source of the Blakesley effect. He's saying the source of the lack of metal in that part of the planchet is due to the uneven distribution of metal and lack of upset during rimming, due to it opposing an incomplete planchet.

So it's not the strike that causes the Blakesley effect, it's that the strike is generally unable to completely hide the Blakesley effect, because the lack of uneven metal distribution is too great to be compensated for by metal flow during the strike."

Yes, a chicken & egg sort of thing. You cannot see the Blakesley effect until the planchet is struck into a coin except it did exist before the coin was struck.
Cluck, cluck, cluck. See my post above. I gave up already and will go with the error experts.

 

CaptHenway, posted: "The Blakesley Effect is a multi-step process. It must be preceded by the creation of a flat blank with some metal missing along the edge in one or more places. This void (or voids) is typically caused by the blanking press creating overlapping holes (a standard clip), or by the blanking press overlapping a straight edge on the strip (a straight clip), or by the blanking press overlapping a rough void in the strip (a ragged clip).

As the incomplete blank is passed through the upsetting mill, the proto rim is formed by the opposing pressures where the diameter is complete from one side to the other and not formed where the diameter is incomplete. This is the Blakesley Effect as seen on an unstruck planchet. In the case where the voids are very minor, partial upsetting may occur."

So the unformed raised rim when the blank becomes a planchet is the Blakesley Effect?

"During the normal upsetting process the diameter of the planchet is reduced slightly. I have measured Type one Blanks and Type Two Planchets and the difference is very minor, but measurable. Where the non-void side of the blank is not squeezed inwards to form the proto rim, the non-moved metal may appear as a very minor "bulge" since the metal on either side of it was moved inwards, but I would not expect it to interfere with the planchet feeding into the collar or survive the strike."

Sounds as if that might happen but as I was never looking for a bulge, so I've never seen it and still does not make sense. I'll need to examine every clipped planchet from now on. I'll be going to the Lakeland, FL show this week and will purchase a few clipped planches (if I see some) to confirm this "bulge."

"During the strike the force of the press will attempt, and typically fail, to reshape the non-upset area of the planchet, the Blakesley Effect, into the rims on the dies. The amount of reshaping that is accomplished depends on the metal involved, the relief of the dies and the pressure setting on the press. The result is typically a coin that shows a Blakesley Effect that survived from the planchet preparation process."

TD

Thanks Tom,

Makes sense. We can see the EFFECT on the coin. But the coin showing it after the strike IS NOT the "Blakesley Effect" itself!"

 

Maybe we should start calling it the Blakesley Syndrome. A group of related symptoms, stemming from a common cause...

 

"I might not know what the Blakesley Effect is, but I know it when I see it."

 

Coin Porn!

 

Yes, you should be able to see the Blakesley Effect on a Clipped Type Two Planchet, assuming of course that the clipped area was missing when the clipped blank went through the upsetting mill and was not a retained clip that separated later.