The Duralex range at Tomkin consists of glasses and tumblers, plates and dishes. Duralex owes its birth to the Saint-Gobain group and the industrial patent for moulded, tempered glass, developed in 1936 in the La Chapelle Saint-Mesmin factory. This industrial process gives the tumbler a perfect transparency and lasting clarity, and makes it practically unbreakable. The Duralex company has been an emblem of a particularly French industrial demand since 1945. Since its creation, the expertise and know-how of its collaborators have given the brand its international renown with its unbreakable tumblers whose pure, simple style is never outmoded. The tempering operation consists of a brutal cooling by ventilation of cold air over the two faces of the glass product, which has been brought beforehand to a temperature of 700° C. This treatment creates in the glass a force which improves most of its physical properties: resistance to mechanical duress (bending, shocks and impacts) and to thermal shocks. MECHANICAL PROPERTIES: the product is 2.5 times more resistant than a fired product of equal thickness. THERMAL: tempered glass can resist a thermal shock of 130°C, while classical glass breaks from a thermal shock of about 40°C. Tempered glass conserves the optical and acoustic properties of each basic product. After being tempered, the glass can no longer be recut or reshaped. Slight deformations may be observed after tempering which are inherent in the manufacturing process.