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Message:: [QUOTE="Sunbird, post: 8286148, member: 116324"]Yeah, that thickness claim must be wrong. (Unless the strike knocks the rim down some from what it was coming out of the upsetting mill, while maybe also reducing the field-to-field thickness, forcing both of the "found" volumes of metal into the die for the design features.) The average thickness doesn't have to be 21% less than the rim thickness to account for the 21% missing volume. There's also the reeded edge. I did some quick math and came up with a 4% volume loss just from the reeded edge, assuming the rim is 1 mm wide (so it accounts for 2 mm of the quarter's 24.26 mm diameter), that the sunken parts of the rim are halfway deep, so 0.5 mm, and that the sunken and raised parts of the rim have equal area around the rim (they're equally wide looking at rim edge-on, and distributed evenly, 50/50). These are all just ballpark guesses, but they might be in the neighborhood of the actual values. I didn't see a thickening in that animated video. The perspective kept changing – they never gave a fixed lateral view of the blank, so I didn't really know what I was seeing, and of course it's just an animation someone created. It would be cool to see a slow-mo video with a fixed angle. Also, the 3D model files of the coins would be super. They must have them, and there are standard file formats like DWG that people can easily open using free viewers, some of which are online.[/QUOTE]