Wiredrawing Dies

In the manufacture of wire, a drawplate (волочильная доска) is usually employed. This tool is a metal plate containing a number of holes, successive 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 on bolts or on the outside of pipes, a thread-cutting die (резьбонарезная плашка) 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 onto a bolt. The corresponding tool for cutting an inside thread, such as that inside a nut, is called a tap (метчик).

Exercises

Exercise 1. Find where in the text it is said about the points given below. Put down the number of a paragraph.

a) matrix;

b) piercing dies;

c) drawplate;

d) nut;

e) tap.

Exercise 2. Match the words and the word combinations on the left with their definitions on the right.

1) dies 2) matrix 3) drawplate 4) tap

a) is the corresponding tool for cutting an inside thread, such as that inside a nut; b) are tools used for the shaping solid materials; c) is the smaller die or punch fitting inside the large die d) is a metal plate containing a number of holes

Exercise 3. Answer the following questions. Find answers in the text. Put the number of the paragraph.

1. Where are dies especially employed?

2. What are the main dies?

3. What are bending and folding dies designed for?

4. Where are matching dies used?

5. What are wire dies?

6. What are wiredrawing dies made from?

7. Why is the thread-cutting die lubricated with oil?

8. What is called a tap?

Exercise 4. Say if the following statements are true or false:

1. In presswork, dies are used in pairs.

2. The metal to be formed, usually a sheet, is placed under the matrix on the press.

3. The simplest dies are piercing dies, used for punching holes.

4. In coining, metal is forced to flow into three matching dies, each of which bears an engraved design.

5. In the manufacture of wire, a drawplate isn’t usually employed.

6. For cutting threads on bolts or on the outside of pipes, a thread-cutting die is used.

Exercise 5. Discussion points.

1. The different kinds of dies and their applications.

2. The similarity of wiredrawing and thread-cutting dies.

3. The structure of a lathe.

4. The main machining methods.

Vocabulary:

electrically driven facility to lubricate spark erosion discharge beam circular cross-section faceplate tolerance to enable stroke to slide lateral displacement idle to execute grinder wheel bonded pass fine conventional fragile die matrix to pierce to punch matching coarse wire tap

с электроприводом приспособление смазывать электроискровая обработка разряд луч круглое поперечное сечение планшайба допуск давать возможность ход скользить боковой смещение на холостом ходу выполнять шлифовальный станок круг, колесо скрепленный проход точный обычный хрупкий матрица, штамп матрица протыкать, прокалывать пробивать отверстие сочетающийся, парный грубый проволока метчик

з електроприводом пристосування змазувати електроіскрова обробка розряд промінь круглий поперечний переріз планшайба допуск давати можливість хід ковзати боковий зміщення на холостому ходу виконувати шліфувальний верстат круг, колесо скріплений прохід точний звичний крихкий матриця, штамп матриця протикати пробивати отвір парний грубий дріт мітчик