What is the difference between natural cracking and man-made damage in car glass?

[DeAshley]

The differences between natural cracking and man-made damage in car glass are as follows: 1. The area of scattered glass fragments differs: man-made damage results in larger fragment areas; due to internal stress without external impact, naturally cracked glass has smaller scattered areas. 2. The initiation points differ: man-made damage typically has initiation points at the glass edges, usually caused by edge damage or hard contact, while natural cracking originates from the center of the glass, featuring a butterfly-wing-like pattern formed by two small polygons with visible black particles along their shared edge.