Can toughened glass be cut on-site?

No, any cutting, drilling, or grinding must be done before the toughening process. Attempting to cut it will cause the glass to shatter.

What is the purpose of the fragmentation test?

To ensure that upon breakage, the glass fractures into numerous small, relatively harmless pieces (minimum 40 pieces in a 50x50mm area) rather than dangerous sharp shards.

How is the shock test conducted?

A 227g steel ball is dropped from a specified height onto the glass specimen to verify its impact resistance.

IS 2553 Part 3

: 1990

Safety Glass - Part 3: Toughened Safety Glass

CurrentSpecializedSpecificationBIMArchitectural · Doors, Windows and Shutters

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This standard specifies the requirements and methods of sampling and testing for toughened safety glass used for general and architectural purposes, including doors, windows, and building facades. It defines acceptable dimensional tolerances, optical quality, impact resistance (shock test), and safety characteristics upon breakage (fragmentation test).

Specifies requirements for toughened safety glass for use in buildings.

Quick Reference Values

Tolerance for 4mm to 6mm nominal thickness± 0.2 mm

Tolerance for 8mm to 12mm nominal thickness± 0.3 mm

Minimum particle count in fragmentation test (50x50mm area)40 particles

Maximum length of longest particle in fragmentation test100 mm

Steel ball weight for shock test227 g ± 2 g

Practical Notes

Toughened glass cannot be cut, drilled, or edge-worked after the tempering process. All such modifications must be completed prior to heat treatment.

A key quality indicator is the fragmentation test; proper toughened glass must shatter into small, relatively blunt fragments rather than large, sharp shards to prevent severe injury.

Bowing or warping is a natural byproduct of the toughening process; ensure the deformation falls within the acceptable limits specified in the code.