Lüders bands are visible, ripple-like surface defects that form when a metal, typically low-carbon steel, transitions from elastic to plastic deformation. They occur at the yield point as localized slip bands propagate across the material. These stretcher strains ruin the cosmetic finish of formed sheet metal parts and indicate uneven yielding.
Heard on the job
We're getting a Lüders band on every hood panel coming off the deep draw press.
Insider tip
A light temper rolling (skin pass) before deep drawing usually prevents these bands from forming.
Also heard as
- Stretcher strains
- Slip bands