Low melting point glass for burner work Red (Soda); Softening temperature: 142°F (600°C); Working temperature: 176°F (800°C); Transparent and opaque: Approx. 0.2 inches (6 mm) diameter x 9.8 inches (25 cm) *Specifications may vary depending on color. This is a basic item, but since it is made by hand, there may be some variations in each product, and if it becomes thinner, there may be 2 pieces in order to match the weight of one piece. Burner work is a method of molding the glass rod with a low melting point and melting it with the flame of the burner, so you can check the change of the glass. Using an iron core, welding colored glass rods to create glass balls.