These types of resins are divided into two groups of Resole and Novolac, based on the molar proportion of raw materials and type of catalyst. Phenolic resins based on alkaline catalysts are known as Resole. They have applications in production of abrasive discs, refractory products, in carbon – magnesite bricks, as adhesive in wooden parts, as a binder in electrical insulation, different types of non-air-drying industrial adhesives, can coating lacquers and etc. Phenolic resins based on acidic catalysts are known as Novolac. They are mostly applied in manufacturing of abrasion resistant materials (roughing wheels and cutting wheels), brake lining, adhesive in brake lining, different types of industrial felts and resin sands. They are supplied both in liquid and solid (powder) form.