Patent ID: 6904659

Claim:
A method for producing a rim hole through first and second planar workpieces wherein the first and second planar workpieces are metal, comprising: forming a penetration opening through the first and second planar workpieces by translating a first punch in a first direction to a first position; translating the first punch, in the first direction, from the first position to a second position relative to a fixed matrix; forming, against a working edge of the fixed matrix, a break away portion in the second planar workpiece; forming a rim hole having a rim using the first planar workpiece such that the rim is formed adjacent to an inner surface of the matrix; and forming the rim into a single layer flange engageable with a bottom surface of the second planar workpiece, wherein the flange is formed using a flange punch and the flange punch engages the flange from a second direction that is linearly opposite to the first direction.