Patent ID: 8322183

Claim:
A necking system comprising: a plurality of necking dies configured for use on an outside of a metal bottle stock, wherein at least one necking die comprises a necking surface and a relief; wherein the necking surface comprises a land portion, a neck radius portion, and a shoulder radius portion, each having an inner diameter; wherein the land portion is between the neck radius portion and the relief and the inner diameter of the land is a minimum diameter of the die; wherein the inner diameters of the neck radius portion and the shoulder radius portion are greater than the inner diameter of the land; wherein the at least one necking die is dimensioned so that when necking the metal bottle stock, the entire land and the relief travel relative to the bottle stock in an axial direction and at least a portion of the relief travels beyond a top of the bottle stock and the land contacts the outside of the bottle stock; and wherein the land has a surface finish Ra ranging from about 8 μin to about 32 μin.