Draw ratio

Where it comes up

• Deep drawn stampingOne-piece cups, cans, shells, and housings drawn from flat blanks, with depth that can exceed the diameter.

Related terms

Blank

A blank is the flat piece of sheet metal cut from coil or sheet before it is formed, drawn, or pierced. Blank size and nesting drive material usage, which is often the largest cost in a stamped part. Blanks are produced by blanking dies, shearing, or laser cutting.

Transfer die

A transfer die is a stamping setup where separate stations each perform one operation and mechanical fingers move the part between them after it is cut from the strip. It handles larger or deeper parts, such as deep drawn shells, that cannot stay attached to a carrier strip.

Springback

Springback is the partial elastic return of formed metal toward its original shape after the forming load is removed. It means bends must be overformed to hit the final angle. Higher-strength steels, stainless, and aluminum spring back more than mild steel does.