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Message:: [QUOTE="Pete Apple, post: 3547746, member: 103982"]Scales which weight to 2 decimals in grams are more helpful. Half (Thickness is of the coil strip prior to blanking and upsetting) Kennedy half dollar coins dated 1965-1969 contain 40% silver Half clad layer (80% +/- 0.6% Ag and 20% +/- 0.6% Cu) Thickness = .254 mm +/- 0.0254 mm (254µm) per side +/- .0508 mm (50.8 µm) Half Copper Core (21.5 +/- 0.6% Ag and 78.5 +/- 0.6% Cu) Thickness = 1.1684 mm (1168.4 µm) +/- 0.0508 mm (50.8 µm) Clad = (8x10.5)+(2x8.96)/10 = 10.192 g/cm³ 0.010192 g/mm³ Half Diameter = 30.61 mm Area = 735.52 mm² Vol Clad Layer = 186.82 mm³ Weight Clad layer = 1.904 g (Periodic Table) Half Total thickness = 2.15 mm . (I think the reason this dimension is not quite as thick as the coin is after minting is that the blanks have not yet been cut or passed through the upsetting mill.) It is to be noted that the amount of silver could vary from between 75% to 85% in the outer layers and from between 20% to 25% in the inner layer. Weight = 11.50 g Half Dollar: Weight/Tolerance 11.500 g +/- 0.400 g = silver clad[/QUOTE]