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 Replies: 13 / Views: 1,988 |
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Valued Member
United States
383 Posts |
Probably just die polish but I found about 8 identical to this one. Ever see anything similar ? It's a 1982 lincoln.    |
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Bedrock of the Community
Australia
21788 Posts |
Can't make up my mind if they are ridges or grooves. Perhaps a shallow angle observation would be better, but that will introduce optical depth of field problems. Maybe very hard to photograph. Perhaps a hand held loupe would be better, then your own opinion. Ridges: harsh die polish, probably to remove hard gunk or rust, and probably with a Dremel. Grooves: PMD, Dremel also probably used. |
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Pillar of the Community
United States
2624 Posts |
I do not think it is die polishing as it is seen on high and low areas. Die polishing should show only on the field.
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Pillar of the Community
Canada
2632 Posts |
A small little rotating wire brush could get into those areas.  |
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Valued Member
 United States
383 Posts |
When I took the pics I laid the coin edge on a couple flips and focused on the higher side
and worked my way down. Didn't turn out to good.
I looked at it under the microscope and the lines on the coin are
definitely raised. They are also stronger in the recessed areas of the coin/high
part of the die. So I would think the die was very crudely cleaned with a rotary tool.
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Pillar of the Community
United States
1234 Posts |
I have seen this type of thing on nickels, my guess on the ones I saw was PMD from a coin sorting machine. |
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Valued Member
United States
383 Posts |
I don't know. The lines are raised on the coin. And there were about
eight in a solid date roll identical. Not similar but identical.
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Pillar of the Community
United States
853 Posts |
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Pillar of the Community
Canada
2632 Posts |
I didnt know these where common, it must be a lathe a mark. Good link Jay
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Bedrock of the Community
Australia
21788 Posts |
We REALLY need to determine if it is grooves or ridges we are looking at.
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Pillar of the Community
United States
2624 Posts |
Quote:
Actually, that's my theory coop. The lathe operator cut the die blank to a taper, used a wire brush or emory cloth to smooth it off, and sent it down the line to be polished.. The final polishing process was skipped or not done correctly for . We'll never know for sure.
I might add that when I polish metals, I use a wire brush as the first step, then switch to sanding belts which get progressively finer until I use the buffing wheel and compound. If you bear down too hard with any of the first steps, you'll have lines that remain.There are a lot of ways wire brush marks could occur. Maineman750 From jay4202472000,s second link. This might also explain the shape of the scratches. Hold the die to the wire brush, turn it hold it to the brush,repeat until you have covered the entire face of the blank die. |
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Valued Member
United States
383 Posts |
Thanks. This is a 1982 copper as well. Interesting.
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Pillar of the Community
Canada
532 Posts |
You can get this affect running a dremel tool with a nylon brush and polish. No doubt it would transfer from a blank but not likely since they don't put that kind of detail on individual blanks. Just my 2 cents
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Pillar of the Community
United States
853 Posts |
The die blank, before being hubbed with the design, not the individual coin blank. The theory takes place in the die creation process.
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Replies: 13 / Views: 1,988 |
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Posted 03/29/2014 11:57 pm
