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<p>[QUOTE="Pete Apple, post: 3573962, member: 103982"]As I understand, you are saying this is a raised feature. That would indicate an indentation on the die which would certainly be from a Rockwell test on the die IF it had other characteristics of a Rockwell Test. I think it does not. The results of a Rockwell test on a die appear differently than a Rockwell Test on a planchet. This is because a Rockwell Test on a die uses a different Rockwell Indenter than on a planchet. It is a Rockwell B (more pressure) as compared to a Rockwell 15T on a planchet.</p><p><br /></p><p>The planchet test uses an indenter which leaves a hemispherical indentation. The ball indenter itself is the size of a 1/16" ball bearing and leaves an indentation about 1 mm in diameter. The indenter used for a B test on a die (because it is harder material) uses a sphero-conical indenter. The mark left will have sloping (not hemispherical) sides of approximately 120 degrees angle from the apex and will be circular at the edges greater than 1 mm in diameter. The mark on this coin does not show that.</p><p><br /></p><p>In addition, Rockwell testing protocol dictates at least 2 tests on a piece of material and you only mention one.</p><p><br /></p><p>This is not a Rockwell Test mark.[/QUOTE]</p><p><br /></p>
[QUOTE="Pete Apple, post: 3573962, member: 103982"]As I understand, you are saying this is a raised feature. That would indicate an indentation on the die which would certainly be from a Rockwell test on the die IF it had other characteristics of a Rockwell Test. I think it does not. The results of a Rockwell test on a die appear differently than a Rockwell Test on a planchet. This is because a Rockwell Test on a die uses a different Rockwell Indenter than on a planchet. It is a Rockwell B (more pressure) as compared to a Rockwell 15T on a planchet. The planchet test uses an indenter which leaves a hemispherical indentation. The ball indenter itself is the size of a 1/16" ball bearing and leaves an indentation about 1 mm in diameter. The indenter used for a B test on a die (because it is harder material) uses a sphero-conical indenter. The mark left will have sloping (not hemispherical) sides of approximately 120 degrees angle from the apex and will be circular at the edges greater than 1 mm in diameter. The mark on this coin does not show that. In addition, Rockwell testing protocol dictates at least 2 tests on a piece of material and you only mention one. This is not a Rockwell Test mark.[/QUOTE]
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