What is the difference between punching and blanking?
In punching, the punched-out piece is the scrap (called a slug) and the sheet with holes is the product. In blanking, the punched-out piece is the product (the blank) and the surrounding sheet is scrap.
Related Terms
Blanking
Blanking is a stamping process where a punch forces metal through a die to cut out a flat shape — the blank — from a sheet. The blank is the desired part; the surrounding sheet is the scrap.
Piercing
Piercing is a stamping operation that cuts holes in a metal part or blank. Unlike blanking, the cut-out material (slug) is discarded and the sheet with holes is the workpiece.
Slug
In stamping, a slug is the scrap piece punched out from the sheet when a hole is made — it is the waste, not the product. Do not confuse with a blank, which is the desired piece.
Metal Blank
A metal blank is a flat piece of metal cut to a specific size or shape, ready to be formed, stamped, machined, or processed further. It's the starting material before a part is finished.