Inventors:
Gerald M. Roeder - Pittsburgh PA
Assignee:
United States Steel Corporation - Pittsburgh PA
International Classification:
B44C 124
Abstract:
In the production of coined sheet products, particularly sheet steel, rolling pressures sufficient to produce a decorative pattern often result in the formation of undesirable "spikes" on the sheet surface. These "spikes" can require numerous paint coatings for effective coverage. Spikes are eliminated by use of a roll design in which the peaks of the pattern roll are provided with a severely sloping draft angle, the minimum angle for "spike" elimination being a function of the roll diameter, the coined depth of the pattern, the thickness and hardness of the sheet itself and the ratio of the volume of the pattern peaks to the pattern valleys.