Flatness (shape) is a frequent acceptance dispute for stainless strip. Clear up the terminology:

1) Waviness: waves along the length — edge wave, center buckle, quarter wave; measured as steepness (mm/m or I-units). 2) Crossbow / lengthwise bow: overall curvature across or along the strip, like a bow. 3) Edge wave: caused by uneven elongation at the edges; very visible after slitting or cut-to-length. 4) Wedge: one edge thicker than the other across the width. 5) Crown: thicker in the middle than at the edges — a hot- and cold-rolling control parameter. 6) Camber: the strip centreline deviates from a straight line.

Acceptance advice:

• Agree flatness limits (waviness/crossbow) in the standard or contract (e.g. ≤10 mm/m or I-units). • For cross-section, agree measurement positions and permitted wedge/crown values. • For cut-to-length, slitting or stamping, specify tighter flatness because downstream operations amplify defects. • Measure with feeler gauges, a surface plate or a shape meter, and keep records.

Flatness is linked to rolling, levelling, cooling and coiling tension — inspect incoming flatness together with process parameters.