Fineblanking is a specialized stamping process developed to overcome certain limitations of conventional stamping, and to create features previously obtained only by machining.

Through the special design of the press and dies, the part is blanked with edges that have a finish similar to machining. Part accuracies, including flatness, profile and holes, are more exact than that of conventionally stamped parts.

Conventional Stamping
In conventional metal stamping a 2-part punch and die set is used. (see the left drawing below). Fineblanking adds two more elements : a clamping or "stinger" plate to prevent roll-off and a counter punch to control deformation as the punch pushes through the plate. Thus, the part is smoothly removed from the strip. This fineblanking process resembles an extrusion process rather than the shearing process of conventional-stamping. This results in a part with superior flatness, smooth edges, less roll-off, and tighter form tolerances. The improved tolerance control results from die to punch clearances of 1/5 or less than that of conventional stamping.

Conventional Stamping	Fineblanking
30% smooth edge part	75-100% smooth edge part

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Last updated: 09/29/2006