A glass failure analysis was performed on a failed oven door made from heat strengthened glass. The glass in the door is connected to the handle with a metal clip placed directly onto the glass. The edges of the clip on the handle were not properly de-burred.
Over time the normal use of the oven allowed penetration of the glass compressive layer by the edge of the clip. Normal use includes opening and closing of the door and differential movement of the glass and metal as a result of the oven heating and cooling. This was worsened due to the presence of a burr on the metal edge that was in contact with the glass.
Cause of Failure: The door failed as a result of two factors.
- The heat strengthened glass was not isolated from the metal handle.
- The metal handle that was in contact with the glass was not properly finished. It had a burr that interacted with the glass surface.