Ears on Cupronickel Cups

IN their paper on the directional properties in cold-rolled and annealed commercial bronze,1 Phillips and Samans suggest that cupronickel, under distinctly different treatments, shows both "45° ears" and "90° ears. " Fig. 1 shows the ears on some cupronickel cups made some 17 years ago for bullet jackets for small arms ammunition. In this case the material heated to 425° C. had "45° ears, while that annealed at 950° C. showed FIG. 1.-CUPRONICKEL, 0.032-in. GAGE, CAST WITH MAGNESIUM. ANNEALED AT TEMPERATURES INDICATED (DEGREES CENTIGRADE) AND CUPPED. long "90° ears" when drawn with the same tools. The method of cupping, the shape of cupping tools, etc., were found to have very little influence on the earing tendency, but the deeper the cup was drawn, the higher the ears would be.