Blanking

Blanking is a metal fabricating process, during which a metal workpiece is removed from the primary metal strip or sheet when it is punched. The material that is removed is the new metal workpiece or blank.

The blanking process forces a metal punch into a die that shears the part from the larger primary metal strip or sheet. A die cut edge normally has four attributes. These include:

(i) burnish     (ii) burr       (iii) fracture          (iv) roll-over

The illustration that follows provides a two-dimensional look at a typical blanking process. Note how the primary metal workpiece remains and the punched part falls out as scrap as the punch enters the die. The scrap drops through the die and is normally collected for recycling

Like many other metal fabricating processes, especially stamping, the waste can be minimized if the tools are designed to nest parts as closely together as possible.

The illustration that follows shows the workpieces that could be created through the blanking process using either sheet or roll as the parent material

The blanking process has some downside effects. These include:

(i) Generating residual cracks along the blanked edges,

(ii) Hardening along the edge of the blanked part or workpiece, and

(iii) Creating excess roll-over and burr if the clearance is excessive.

The most common materials used for blanking include aluminum, brass, bronze, mild steel, and stainless steel. Due to its softness, aluminum is an excellent material to be used in the blanking process.

A blanking die consists of a single, or multiple, pairs of mating dies. The illustration that follows shows a potential die set. Notice the large amount of scrap material that is generated. Tools are expensive for blanking so it is critical that the tooling be created correctly holding tolerances while minimizing scrap, the first time.

Credit:- www.advantagefabricatedmetals.com/blanking-process.html