III. Find the Infinitive and state its function.

1. The quantity of water which is used varies with the kind of product to be made.

2. They suggested performing an experiment to prove their point.

3. To understand the size of amicron it may be pointed out that a particleof even 50 microns is microscopic.

4. To design plans of new buildings is the work of an architect.

5. He often forgot to register the result of experiments.

6. A thermometer is a device to show the temperature.

7. Each type of atom is known to have a name and symbol.

8. The device is unlikely to operate.

9. The device to operate was unknown to him.

10. To carry out the task they had to work for three hours.

Text 9

TURNING, DRILLING AND BORING MACHINES

The engine lathe is the oldest and most common turning machine. It is used for shaping the external surface of a cylindrical part by rotating the work-piece against a cutting tool. The turret lathe carries a number of cutting tools that can be used in sequence to shape, drill, bore, ream, and cut threads on both exterior and interior cylindrical surfaces. A fully automatic turning machine can feed in the work-piece and perform all cutting operations. A duplicating lathe can replicate quantities of an identical shape by using a tracing mecha­nism and a template.

The drill press, the most common form of drilling machine, is essentially one or more rotating drill heads mounted in the tool holder, which can be moved against the work-piece. Similar machines perform such operations as boring, finishing a drilled hole with a rotat­ing, single-edged cutting tool; reaming (which is a boring operation performed to very high tolerances); and tapping, cutting an interior screw thread. Many drilling operations can be done with the turret lathe. Special boring mills bore holes in work-pieces that are too large to fit a lathe.

Words and word combinations

in sequence – по черзі

replicate - копіювати

EXERCISES

I. Give the Ukrainian equivalents:

1.	the engine lathe
2.	a turning machine
3.	shaping
4.	an external surface
5.	rotating
6.	a work-piece
7.	a cutting tool
8.	the turret lathe
9.	to drill
10.	to bore
11.	to ream
12.	to cut threads
13.	to feed in
14.	a duplicating lathe
15.	a tracing mecha­nism
16.	a template
17.	the drill press
18.	finishing
19.	a single-edged cutting tool
20.	tapping
21.	an interior screw thread
22.	a boring mills

II. Give the English equivalents.

1) токарний верстат......................................................

2) фасонування зовнішніх та внутрішніх поверхонь...........................................................................................................................................................

3) нарізання різьби.........................................................................................................................

4) свердління...................................................................................................................................

5) розточка....................................................................................................................................

6) розшивка.....................................................................................................................................

7) вироби,ідентичні за формою.....................................................................................................

8) шаблон........................................................................................................................................

9) шляхом обробки заготів різцем................................................................................................