Grinders

Technically, grinding wheels are a subset of cutting tools, as grinding is a true metalcutting process. Grinding wheels are usually made of abrasives such as aluminium oxide, silicon carbide, emery, or diamonds. An angle grinder or a side grinder is a handheld power tool used for cutting, grinding and polishing. The motor drives a geared head on which an abrasive disc is mounted that can be replaced when worn.

Angle grinders may be used both for removing excess material off a piece or simply cutting into a piece. There are many different kinds of disks that are used for various materials and tasks. Angle grinders are widely used in metalworking and construction, as well as in emergency rescues. There are a large variety of angle grinders depending on the power source – pneumatic or electric and the disk size.

Ram

Hammers are classified as mechanical and air-and-steam hammers. The part of the hummer, which serves as a rigid support during forging, is called the anvil block. The heavy falling part of the hammer is called the ram. The lower part of the ram, which comes into direct contact with the forging, is called the bottom die. The heavier the falling part of a hammer, and the greater the height and velocity of the fall, the greater will be the force of the blow of the hammer.

Die

Die (manufacturing) is a material-shaping device. A die is a specialized tool used in manufacturing industries to cut or shape material using a press. Products made with dies range from simple to complex units used in advanced technology. The die is a metal block that is used for forming materials like sheet metal and plastic. Die operations are often named after the specific type of the die that performs the operation. For example, a bending operation is performed by a bending die. Some dies may incorporate multiple operation types. The bending operation is the act of bending blanks at a predetermined angle. A blanking die produces a flat piece of material by cutting the desired shape in one operation. The finish part is referred to as a blank. Generally, a blanking die may only cut the outside contour of a part without internal features. A compound die has the die block (matrix) mounted on a punch plate with perforators which allows the cutting of internal and external part features on a single press stroke. Forming dies bend the blank along a curved surface.

Exercise 1. Translate the word and word combinations with Gerund into Russian:

machining, cutting, cutting tool, milling, milling cutter, metal-cutting process, cutting edge, cutting face, grinding tool, cutting surface, milling bit, cutting teeth, roughing mill, hobbing cutter, hobbing machine, grinding wheel, polishing, removing excess material, metal working, forging, manufacturing, manufacturing industries, forming, bending, bending operation, bending die.

Exercise 2. Complete the sentences:

1. A cutting tool is the tool used to …

2. Cutting tools must be harder than …

3. The tool must withstand …

4. The tool must have a specific …

5. Non-grinding cutting tools are classified as …

6. The flutes of the milling bit are …

7. The flutes of a milling cutter are almost always …

8. Grinding wheels are usually made of …

9. Angle grinders are widely used in …

10. A die is a specialized tool used to …

Exercise 3. Use the verbs in brackets in the proper forms of Indefinite Tense Active and Passive:

1. A cutting tool is a tool that (to use) to remove metal from the workpiece.

2. Cutting tools (to make) of hard material.

3. As a rule the tool (to withstand) high heating.

4. Any cutting tool (to have) a specific geometry.

5. Non-grinding cutting tools (to classified) into linear and rotary.

6. Some cutting tools (to combine) function of linear and rotary motion.

7. The flutes of the milling bit (to be) helical grooves.

8. The shank of a cutter (to hold) and (to locate) in the tool holder.

9. Side-and-face cutter (to design) with cutting teeth on its side.

10. Grinding wheels usually (to make) of abrasive materials.

11. The motor (to drive) a geared head on which an abrasive disk (to mount).

12. Cutting disks (to divide) into different kinds.

13. The heavy falling part of the hammer (to call) the ram.

14. Some materials (to shape) by using a press.

15. Sheets metal and plastics (to form) by a metal block which (to call) a die.

Exercise 4. Find in the text the sentences that correspond to the following statements:

1. A workpiece is machined with a cutting tool by removing metal from it.

2. Cutting tool should not be softer than the machined workpiece.

3. Only the edges of a cutting tool should touch the workpiece by processing.

4. Broaches are non-grinding cutting tools.

5. Cutting tools are made of hard grades of steels.

6. The speed of removing materials depends on the number of teeth of a cutter.

7. The position of flutes influences the accuracy and surface quality of details.

8. Angle grinders are used not only in metal-cutting but in emergency situations,

9. The blow of hammer during forging is dependent on the height and velocity of the fall.

10. Various dies may perform operations changing the shape of material.

Exercise 5. Find English equivalent to the Russian word:

1. резец а) broach c) blade

b) saw d) cutter;

2. срез a) cut c) shear

b) edge d) milling;

3. развертка a) cuntersink c) reamer

b) die d) cutter;

4. головка а) head c) shank

b) bit d) angle;

5. трение, a) contact c) touching

касание резца b) dragging d) friction;

6. паз (фрезы) a) shank c) groove

b) bit d) slot;

7. заготовка а) workpiece c) blank

b) slab d) ram;

8. сорт стали a) type c) kind

b) grade d) variety.

Exercise 6. Translate into English:

1. Разновидностью режущего инструмента является фреза.

2. Режущие инструменты должны изготавливаться из твердых материалов.

3. Форма и угол резания имеют большое значение.

4. В зависимости от операции режущими инструментами являются метчики, пуансоны, развертки.

5. Для изготовления режущих инструментов используются различные сорта сталей.

6. Фреза – это стержень или диск с несколькими зубцами.

7. Зубцы фрезы должны иметь определенное расположение, влияющее на точность и качество обработки деталей.

8. Торцевые фрезы имеют зубцы, как на конце, так и с боков.

9. Абразивными материалами для шлифовальных станков являются алюминий, силикон, наждак и алмаз.

10. Вырубной штамп производит детали различной конфигурации.

Speaking:

Exercise 7. Give the summary of the text, using key vocabulary and tell about:

1. the functions of cutting tools;

2. characteristics of cutting tools;

3. types of cutting tools;

4. geometry of milling cutters;

5. the principle of work of mechanical hammers;

6. the structure and usage of grinding tools;

7. the types and manufactural application of dies.

Checklist for Section IV:

1. How are the degrees of comparison of adjectives formed?

2. How is Gerund translated into Russian?

3. What are the types of cutting tools?

4. What are their functions?

Section V

The History of Lathes Emergence

Grammar: Functions of Infinitive.

Word-formation: suffix –al.

Speaking: The stages of lathes invention.

Practise the reading of the words:

design	[dI′zaIn]
prototype	[′proutə′taIp]
perspective	[pə:′spektIv]
unfortunately	[Λn′fɔ:tnItlI]
original	[ə′rIdჳənl]
tsar	[zɑ:]
amazingly	[ə′meIzIηlI ]
numerous	[′nju:mərəs]
conjunction	[kən′dჳΛηkən]
specialized	[′speəlaIzd]
commercial	[kə′mə:əl]
accurate	[′ækjurIt]