Glass Basics: Scoring and Separating Recommendations0 pages

Glass Basics:
Scoring and Separating Recommendations
Technical Information Paper

TIP 305
Issued: November 2004
Supercedes: xxxxx

Scoring is performed to separate a sheet of glass into smaller pieces with good quality edges. A score wheel, and
typically a scoring machine, is used to create a small “flaw” or shallow crack by drawing the score wheel across
the glass under load. This crack is called a median crack.
The glass is then bent to extend the median crack through the thickness of the sheet, creating two pieces. The quality
of the median crack controls the ease of separation and the quality of the edges. The crack should be continuous
throughout the length of the score and have a consistent depth. This provides ease of separation and minimizes
unwanted chips and cracks.
Scribe load
Radius
Tip angle
Surface

Velocity

Median crack
Figure 1. Downward pressure on
the scoring wheel should be
applied in a manner that creates a
median crack of a consistent depth
throughout the length of the score.

Figure 2. A photo of a score
wheel in the process of creating a
median crack

Figure 3. After creating the
median crack , applying
downward pressure on both sides
of the scoreline will enable glass
separation.

TIP 305 | 1