A blank is a metal disc that has been gang punched from a metal strip. This metal disc or blank is commonly referred to as a Type I planchet.
This dime blank bypassed the upset mill and was therefore never transformed into a planchet. The edge is rough, with the “cut-and-tear” texture typical of a blank. One face of the blank has a slightly downturned perimeter. This is from the bottom side of the coin metal strip. The slight downwarping of the blank’s perimeter is produced when the disc is forced through a hole in a perforated base plate.
A planchet is a blank that has been through the upset milling machine. This disc of metal is referred to as a Type II planchet.
This dime planchet shows the upset proto-rim that is produced as the coin is rolled and squeezed within the upset mill. The edge is smoothed out during its passage. In vertical cross-section, the edge has the shape of a low trapezoid. In other words it has sloping sides that meet a flat apex.