This document provides a lesson on common metals used in mechanical engineering. It defines the three main groups of metals as ferrous, non-ferrous, and alloys. Ferrous metals contain iron while non-ferrous metals do not. Examples of ferrous metals include cast iron, wrought iron, and mild steel. Common non-ferrous metals are aluminum, copper, lead, tin, and zinc. Alloys are mixtures of two or more metals such as brass and bronze. The document describes the properties, colors, and common uses of various metals to teach students about materials selection in engineering.

1. Mechanical EngineeringMechanical Engineering
TechnologyTechnology
LessonLesson
Topic:Topic: Common MetalsCommon Metals
Have fun learningHave fun learning

2. Objectives of thisObjectives of this
LessonLesson
By the end of this lesson you should beBy the end of this lesson you should be
able to:able to:
1)1) Define the three main groups of commonDefine the three main groups of common
metalsmetals
2)2) Identify some common metalsIdentify some common metals
3)3) State the colour, properties and uses ofState the colour, properties and uses of
common metalscommon metals

3. Common MetalsCommon Metals
• The importance of metals to man inThe importance of metals to man in
today's world cannot betoday's world cannot be
overemphasized because we use themoveremphasized because we use them
in our everyday life.in our everyday life.
• Metals are divided into three mainMetals are divided into three main
groups;groups;
• Ferrous,Ferrous,
• Non-ferrousNon-ferrous

4. Ferrous MetalsFerrous Metals
These containThese contain
mainly iron and theymainly iron and they
rust easily whenrust easily when
exposed to air.exposed to air.

5. Non-Ferrous MetalsNon-Ferrous Metals
•These contain little orThese contain little or
no iron and they do notno iron and they do not
rust when exposed torust when exposed to
air.air.
Space rocket

6. AlloysAlloys
•These are a mixture ofThese are a mixture of
two or more metals.two or more metals.
They may be ferrous orThey may be ferrous or
non- ferrous.non- ferrous.
Art work

7. Examples of FerrousExamples of Ferrous
MetalsMetals
•Cast ironCast iron
•Wrought ironWrought iron
•Mild steelMild steel

8. Cast ironCast iron
Gray or white in colourGray or white in colour
Very brittle with a hard outer coreVery brittle with a hard outer core
Use for making machine slide-Use for making machine slide-
ways, beds, vice and supportways, beds, vice and support
brackets.brackets.
Cast iron vice

9. Wrought ironWrought iron
• Light grey in colourLight grey in colour
• Very malleable and ductileVery malleable and ductile
• Used for making grill gates,Used for making grill gates,
crane hooks and bridges.crane hooks and bridges.

10. Mild steelMild steel
Gray in colour, showsGray in colour, shows
silvery when machinedsilvery when machined
Very ductile and malleableVery ductile and malleable
Used for making nuts, gears,Used for making nuts, gears,
bolts, grill, buildings and forbolts, grill, buildings and for
general engineeringgeneral engineering
purposespurposes Spur gears

11. Activity # 1Activity # 1
• INSTRUCTION: Match the following items correctly by writingINSTRUCTION: Match the following items correctly by writing
the letter A, B or C in the appropriate box on the right.the letter A, B or C in the appropriate box on the right.
Metals that do not contain iron
Mixture of metals
alloys
Non-ferrous
ferrous
Metals that contain iron
Activity # 1 Answers
A
B
C

12. Examples of non-ferrous metals
Aluminium
Copper
Lead
Tin
Zinc
Aluminium blocks in stock

13. Aluminium
 Light gray in colour,shows silvery when
machined
 Very ductile,malleable,soft,light in weight and
is a good conductor of heat and electricity
 Used for making pots, pans, furniture,
aircraft parts, car parts and television
antennas.
Aircraft manufacturing

14. Copper
 Brownish pink in colourBrownish pink in colour
 A very good conductor of heat andA very good conductor of heat and
electricity, malleable and ductileelectricity, malleable and ductile
 Used for making electrical wires,Used for making electrical wires,
soldering iron, electrical coils andsoldering iron, electrical coils and
tubes.tubes.
Copper coil

15. LeadLead
• Bluish grey in colourBluish grey in colour
• Poisonous, has a dull metallic luster,Poisonous, has a dull metallic luster,
plastic- like, resistant to acids and veryplastic- like, resistant to acids and very
heavyheavy
• Used for making weights, containersUsed for making weights, containers
for acids and car batteries.for acids and car batteries.
Car battery

16. TinTin
• Silvery in colourSilvery in colour
• Not used much on its own, veryNot used much on its own, very
malleable and ductilemalleable and ductile
• Used as a coating for steel to make tinUsed as a coating for steel to make tin
plate which is then used to make foodplate which is then used to make food
stuff container for milk, mackerel,stuff container for milk, mackerel,
drinks and juice.drinks and juice.

17. Zinc
Bluish white in colour
Somewhat hard and brittle.
Like tin, not used much on its own. Used
as a coating for mild steel (galvanizing)
which is used for making sheets for
roofing

18. Examples of Alloys
• Brass
• Bronze
Bicycle-made using alloys

19. BrassBrass
• Brass is an alloy of copper and zincBrass is an alloy of copper and zinc
• Yellow in colour, malleable and is aYellow in colour, malleable and is a
good conductor of electricity.good conductor of electricity.
• Used for making screws, door locks,Used for making screws, door locks,
jewellery and some electricaljewellery and some electrical
components.components.

20. BronzeBronze
• Bronze is a mixture of copper and tinBronze is a mixture of copper and tin
• Dark yellow in colour, ductile and is a goodDark yellow in colour, ductile and is a good
conductor of heat.conductor of heat.
• Used for making water pipe fittings, gasUsed for making water pipe fittings, gas
welding equipment, weapons, medals andwelding equipment, weapons, medals and
trophiestrophies
Early weapons

21. QuizQuiz
Read the statements below. If the statement isRead the statements below. If the statement is
“true’’ write “T”, if “false" write “F”.“true’’ write “T”, if “false" write “F”.
1)1) Ferrous metals contain no iron.Ferrous metals contain no iron.
2)2) Alloys contain two or more metals.Alloys contain two or more metals.
3)3) Cast iron is a ferrous metal.Cast iron is a ferrous metal.
4)4) Copper is a poor conductor of heat andCopper is a poor conductor of heat and
electricity.electricity.
5)5) Lead is a poisonous metal.Lead is a poisonous metal.
For answers click hereFor answers click here
Answers

22. Activity # 1 AnswersActivity # 1 Answers
Matching items
Metals that do not contain iron
Mixture of metals
alloys
Non-ferrous
ferrous
Metals that contain iron
A
B
C
C
B
A

23. Answers for quiz
• 1 F
• 2 T
• 3 T
• 4 F
• 5 T
Congratulation

24. Assignment
• State the properties, appearance and uses of
gold.
• This should be typed
• No more than two pages
• Should contain at leased one picture
• Due date: one week from now.

25. Lesson summary
• From this lesson we learnt that common metals
are very important in our everyday life.
• Metals are used in the transportation industry in
manufacturing motor vehicle, aircrafts, etc.
• Used for making kitchen utensils and many
appliances.
• We are able to identify metals by their colours
and properties.

26. references
• tubeshttp://www.bbsheetmetal.com/product.php?prID=19
• 2005 Encarta DVD library
• Thomas G. H. Metalwork Technology, Metric edition.

27. ASSIGNMENT
• Research on a mechanical engineer
• Find a picture of the person
• The product that the person designed

28. End of lesson
• I hope that you have found it interesting
and informative.