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<p>[QUOTE=&quot;Pete Apple, post: 3547944, member: 103982&quot;]In my thinking about this, I have also rejected the possibility that it is a Rockwell Test Mark on the die. To be a rockwell test on a die (which would be expected with a raised area), the shape should be sphero-conical with sloping sides of 120⁰. If it ever was that shape, it has of course been destroyed by the damage to the coin. However, I think that a test mark with damage would not resemble this feature at all when the shape before damage is considered.</p><p><br /></p><p>It is also too close to the edge of the coin (i.e. die) to be a Rockwell Test because of the following testing protocol I quoted in a paper I wrote on the subject: “Because of the relatively small volume of material affected by the hardness test, care must be taken to obtain representative test data. Several measurements should be taken to avoid a false reading caused by microstructural inconsistencies such as hard beryllide particles or grain boundaries. Hardness should be checked on cross sections when nonuniform cold work causes high surface hardness. The depth of penetration of the indenter must be less than 10% of the metal thickness, and the reading must be taken at least two indenter diameters from an edge. (Materion Corporation, 9/4/2015).&quot;[/QUOTE]</p><p><br /></p>

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