Profile: National Trading Co. specializes in offering bitumen, transformer oil and metal scrap. Bitumen is basically the mixture of organic liquids which is highly viscous, black, sticky and composed primarily of highly condensed polycyclic aromatic hydrocarbons. The bitumen asphalt is used for various applications such as paving roads, roof lining and bituminous waterproofing. Our electrical transformer oil is extensively used in power transformers as it is stable at high temperatures and also has electrical insulating properties.