---
title: "Heat Stregthened: Performance"
description: "### Performance - Heat-strengthened glass: - is more resistant to thermal stress than annealed glass. It can withstand differences in temperature of approximately 100°C - more resistant to breakage due to bending (70 N/mm²) than annealed glass - breaks into…"
url: "https://metalcoglazing.com/products-docs/heat-stregthened-performance/"
updated: "2024-05-23"
category: TEMPERED GLASS / Heat Strengthened Glass
---

# Heat Stregthened: Performance

### Performance

- Heat-strengthened glass:
  - is more resistant to thermal stress than annealed glass. It can withstand differences in temperature of approximately 100°C
  - more resistant to breakage due to bending (70 N/mm²) than annealed glass
  - breaks into large sharp pieces which can cause injury
  Accordingly, heat-strengthened glasses are not safety glasses. Heat-strengthened glasses break in a crazed pattern.
- Magnetron coatings which can be thermally treated must be heat strengthened to achieve the stated performance (fragmentation, optical, Ug value)
- The light, thermal and energy performance of thermally toughened glasses is exactly the same as that of the same annealed glass.

#### Finishing

- Edge finishing The following edge finishings are available for heat-strengthened glasses:
  - Arrissed edges
  - Ground edges but some bright areas permitted
  - Ground edges but – no bright areas
  - Polished edges
  For buildings, the heat-strengthened glass will be supplied as standard with arrissed edges but depending on the requirements of the particular application, a different finish may be possible. Ground polished edges are normally only destined for nonbuilding applications.
- Other finishing options
  - Holes
  - Notches