Manufacturing at division Kovohutě Čelákovice, has changed a lot since the company was established in 1860. The manufacture of semi-products from copper and its alloys, however, has always been the focal point.
At our manufacturing outlet you can buy a wide range of our most common products. This outlet serves primarily our smaller volume customers. All products have a Quality Certificate including, if need be, a metallurgical certificate and any required test results.
Manufacturing semi-products are divided according to chemical composition:
Semi-products from pure copper have high electrical as well as thermal conductivity. They have a long life because of good corrosion resistance. Pure copper is made in several grades. It is graded according to the content of other elements. Impurities, which range in amounts from a tenth to a thousandth of a percent, lower copper's conductivity.
Semi-products from copper alloyed by other elements
Semi-products from copper alloyed with other elements have a higher strength than pure copper. Additional elements usually also increase chemical and abrasion resistance and allow for penetration and bonding, as in the case with solders. Additional elements can reduce the danger of what is called hydrogen fault. Silver, manganese, silicon, nickel, arsenic, and phosphorus are used as alloying elements, their combination making up about 3 percent of the content. If the amount of these elements is higher, the resulting alloys are considered to be bronzes.
Semi-products from brass
Semi-products from brass contain copper and zinc as basic metals. Zinc ranges from 5 to 44 percent. When brass contains copper and zinc only, it is called binary brass. In practice, additions of other metals make for a wide range of brasses ("legged" brasses). These alloying elements improve or change the properties of brass. Lead is one of the most common additions. If the content is up to 3 percent, the brass's workability (free-cutting) and shapability when heated are better. Other metals which can be added include aluminum (for corrosion resistance), silicon (for ease of soldering), and manganese (for abrasion resistance). Brass is the most flexible alloy because: it is easily shaped; it is easy to work with; it is corrosion resistant; it is colorful; it is suitable for grinding, buffing and blasting. And it is suitable for soldering. The prices for different brasses are relatively reasonable.
Semi-products from bronze
Semi-products from bronze have high rigidity, elasticity, and good friction properties. They are abrasion and corrosion resistant, and some of them can be heat treated to achieve higher rigidity. (The classic tin bronze (alloy of copper and tin) can be replaced sometimes by aluminum with the addition of manganese and iron or nickel.) In this group of bronze semi-products, there are special bronzes with various added elements.