Sweden's most valuable assets are forests, mines (especially iron, but copper has also been important), and in modern days hydroelectric power. The metallurgic industry was started in the 16th and 17th centuries, and through the ages Sweden has been known as one of the biggest iron exporters in the world. A mechanical industry came with the industrial revolution in the 19th Century, and Swedish products such as steel (Sandvik), paper (SCA and others), cars (Volvo and Saab), ball bearings (SKF), electrical equipment (ASEA, now ABB), telephone equipment (Ericsson), refrigerators (Electrolux) and cameras (Hasselblad) have become well known. Beside cars Saab has also produced computers and aircrafts.
More recently also medical equipment (Gambro), medicine (Pharmacia, Astra), chemical industry (Nobel, AGA) and food-processing equipment (Tetra-Pak, Alfa-Laval) has been developed and marketed by Swedish companies. During the 1980s and 1990s there has been some debate in Sweden over the reasons why new products (as for instance a flat screen for television and computers) has to find foreign companies for investments and marketing.
After particularly good years from World-War II to the early 1970s, Sweden has then seen branch after branch of the industry to lose competitive capacity. Textile industry, skinn industry and shipyards have almost disappeared. During the 1990s the mining industry has went through a period of radical reorganization.
The wide forests are mainly used for production of paper, contributing with about 20% of Sweden's export (some wood export included).