Architectural glass light in industrial factories. Annealed glass is glass without internal stresses caused by heat treatment, i.e., rapid cooling, or by toughening or heat strengthening. Glass becomes annealed if it is heated above a transition point then allowed to cool slowly, without being quenched. Float glass is annealed during the process of manufacture. However, most toughened glass is made from float glass that has been specially heat-treated. Annealed glass breaks into large, jagged shards that can cause serious injury and is considered a hazard in architectural applications. Building codes in many parts of the world restrict the use of annealed glass
Glass-coated wire or oil. However. there are some apparatuses that can bypass some of these problems by heating the glass and the metal in separate chambers which allows for the use of metals with high melting points. Around the 1950s the Taylor-Ulitovski process was changed to a continuous feeding process of the materials in order to make these wires on a mass production scale. Metal cores in the range 1 to 120 micrometres with a glass coating a few micrometres in diameter can be readily produced by this method. Glass-coated microwires successfully produced by this method include copper, silver, gold, iron, platinum,