21.What is the density of a material?

22.What are the units of density? Where low density is needed? 23.What are the densities of water, aluminium and steel?

24.A measure of what properties is stiffness? When stiffness is important? 25.What is Young modulus?

26.What is strength?

27.What is yield strength? Why fracture trength is always greater than yield strength?

What if ductility? Give the examples of ductile materials. Give the examples of brittle materials,

28.What is toughness?

29.What properties of steel are necessary for the manufacturing of: a) springs, b) ear body parts, e) bolts and nuts, d) cutting tools?

30.Where is aluminium mostly used because of its light weight?

Machine-Tools

1.What is a machine?

2.What simple machines do you know?

3.What is the main part of every machine?

4.What is milling machine used for?

5.What main parts does the milling machine consist of?

6.How are milling machines classified?

7.What part is called knee?

8.What is the knee used for?

9.What part rests upon the knee?

10.What is grinding machine used for?

11.How are grinding machines classified?

12.What are the characteristic features of a universal cylindrical grinder? 13.What is the main feature of grinding machines?

14.What are bench grinders used for?

15.For what type of work is the cylindrical grinder used?

16.What types of grinding machines are used for finishing internal surfaces of cylindrical or conical shape?

17.Why are centreless grinding machines called so? 18.What type of work is the surface grinder designed for?

Manufacturing and Technological Processes

1. What are the main processes of metal forming?

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