READING Text 1 1. Read the text about dies. Read the statements after the text and decide whether they are true (T) or false (F). If the sentence is false – write the correct variant. DIES Dies are tools used for shaping solid materials, especially those employed in the pressworking of cold metals. In presswork, dies are used in pairs. The smaller die, or punch, fits inside the larger die, called the matrix, or, simply the die. The metal to be formed, usually a sheet, is placed over the matrix on the press. The punch is mounted on the press and moves down by hydraulic or mechanical force. A number of different forms of dies are employed for different operations. The simplest are piercing dies, used for punching holes. Bending and folding dies are designed to make single or compound bends. A combination die is designed to perform more than one of the above operations in one stroke of the press. A progressive die permits successive forming operations with the same die. In cooling, metal is forced to flow into two matching dies, each of which bears an engrvad design. WIREDRAWING DIES In the manufacture of the wire, a draw plate is usually employed. This tool is a metal plate containing a number of holes, successively less in diameter and known as wire dies. A piece of metal is pulled through the largest die to make a coarse wire. This wire is then drawn through the smaller hole, and then the next, until the wire is reduced to the desired measurement. Wiredrawing dies are made from extremely hard materials, such as tungsten carbide or diamonds. THREAD-CUTTING DIES For cutting threads or bolts or on the outside of pipes, a thread-cutting die is used. It is usually made of hardened steel in the form of a round plate with a hole in the centre. The hole has a thread. To cut an outside thread, the die is lubricated with oil and simply screwed onto an unthreaded bolt or piece of pipe, the same way a nut is screwed on a bolt. The corresponding tool for cutting an inside thread, such as that inside a nut, is called a tap. 1. Piercing dies are used for manufacturing wires. 2. The tool for cutting an inside thread is known as wire dies. 3. The tool for cutting a thread inside a nut is called a tap. 4. Wires are made from extremely hard materials, such as tungsten carbide or diamonds. 5. A draw plate is usually employed in manufacture of wires. 6. A thread-cutting die is made of hardened steel in the form of a round plate with a hole in the centre. 7. In presswork, dies are used alone. 8. Dies are tools used for shaping soft materials 9. Wires are drawn from the successive number of holes. 10. Bending and folding dies are designed to make single or compound bends. Text 2 2. A. Read the text and answer the questions. 1. What is a non-ferrous metal? 2. What is copper extracted from? 3. Where is copper used? 4. What are the properties of tin? 5. Why is tin used for coating other metals? B. Correct the sentences below. 1. We use copper to make carrying utensils. 2. Lead is a hard malleable, ductile element. 3. Tin was the fourth metal discovered by man. 4. Tin is used to extract other metals. 5. Copper doesn’t rust widely, so it lasts a very long time. THE FIRST NON-FERROUS METALS Non-ferrous metals are the metals not composed of or containing iron. Copper was one of the first metals to be used. In its natural form, copper occurs in the ground as copper ore, a mineral. But this ore contains only 0.5–1 per cent of the metal. The rest is rock.
of copper a year. This means that more than a thousand million tonnes of ore have to be removed from the ground and the pure copper extracted. Most copper is extracted from a compound of iron, sulphur, and copper called sulphide ore. Copper is a good conductor of heat and electricity. We use it to make cooling utensils and all sorts of pipes for carrying hot water, both in homes and in industry. We also use it to j make different kinds of electrical devices, such as lightning conductors and the electric coils in motors. Copper does not rust easily, so it lasts a very long time. Such metals as lead and tin were widely known in Roman times. Lead is a soft malleable, ductile, bluish-white, dense metallic element, extracted chiefly from galena and used in containers and pipes for corrosives, in solder and type metal, bullets, radiation shielding, paints and anti-knock compounds. Some Roman aqueducts still stand today because they were lined with lead and lead does not rust. Many thousands of tonnes were used in a single aqueduct. So much lead was used in water-supply systems that eventually the Romans suffered some lead-poisoning. Tin was the fifth metal discovered by man. It is a malleable, silvery metallic element obtained chiefly from cassiterite. It is used to coat other metals to prevent corrosion, and forms part of numerous alloys such as soft solder, pewter, type metal and bronze. For example, pewter, an alloy of lead and tin, was widely used in Roman times to make cups and dishes. VOCABULARY AND GRAMMAR 3. A. Choose the correct translation of the underlined word. 1. They helped to solve this problem. a) ðåøèòü b) ðåøèâ ñ) ðåøàÿ 2. To do the translation better you can use a dictionary. a) äåëàòü b) äëÿ òîãî, ÷òîáû ñäåëàòü ñ) äåëàÿ 3. To do this operation became possible by means of new equipment. à) ñäåëàòü, âûïîëíèòü b) äåëàÿ, âûïîëíÿÿ ñ) âûïîëíåíèå 4. The device to be introduced is made by our engineer. a) äëÿ òîãî, ÷òîáû ïðåäñòàâèòü b) êîòîðîå áóäåò ïðåäñòàâëåíî ñ) ïðåäñòàâëÿÿ 5. To solve this problem they made many experiments. a) äëÿ òîãî, ÷òîáû ðåøèòü b) êîòîðûå ðåøàþò ñ) ðåøåíèå 6. To solve this problem is very important. a) äëÿ òîãî, ÷òîáû ðåøèòü b) êîòîðûå ðåøàþò ñ) ðåøåíèå 7. Our task is to solve this problem. a) äëÿ òîãî, ÷òîáû ðåøèòü b) ðåøèòü ñ) ðåøåíèå B. Match the words with their definitions. Dies, the matrix, a tap 1. – are tools used for shaping solid materials. 2. – is the smaller die, or punch, which fits inside the larger die. 3. – is the corresponding tool for cutting an inside thread, such as that inside a nut. TRANSLATION 4. Translate the following sentences into Russian. 1. To design new buildings is the work of an architect. 2. To measure volumes we must know the dimensions of a body. 3. To give the necessary output the plant needed new modern methods. 4. The result to be expected is important for our investigation. 5. Our plant was the first to install the new equipment. 6. To carry out such a complicated experiment is not an easy task. 7. It’s necessary for an engineer to know a foreign language. 8. The device to be tested has been brought to our laboratory. 9. He appears to know physics better than the others. 10. The conference is reported to be held in February. WRITING 5. Write an abstract of the text below. THE PROCESS OF WIREDRAWING The wire drawing process is quite simple in concept. The wire is prepared by shrinking the beginning of it, by hammering, filing, rolling or swaging, so that it will fit through the die; the wire is then pulled through the die. As the wire is pulled through the die, its volume remains the same, so as the diameter decreases, the length increases. Usually the wire will require more than one draw, through successively smaller dies, to reach the desired size. The American wire gauge scale is based on this. This can be done on a small scale with a draw plate,