Common causes of edge cracking:

1) Hot-rolled edge temperature too low or edge defects not trimmed, which propagate during cold rolling. 2) Total cold-rolling reduction too large, or improper pass distribution. 3) Improper slitting tool clearance, or microcracks already present at the incoming strip edges. 4) Excessive coiling tension causing stress concentration at the edges.

Prevention: require the steel mill to trim edges cleanly, control the cold-rolling reduction schedule, and inspect edge quality before slitting; when edge cracking is found, trace the heat number and rolling records.