properties+uses-of-metals

5/24/2018 properties+uses-of-metals

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CHAPTER 1

PROPERTIES AND USES OF METAL

In the seabees, Steelworkers are the resident

experts on the properties and uses of metal. We lay

airf ields, erect towers and storage tanks, assemble

pontoon causeways, and construct buildings. We use

our expertise to repair metal i tems, resurface worn

machinery parts, and fabricate all types of metal

objects. To accomplish these tasks proficiently, one

must possess a sound working knowledge of va rious

metals and their properties. As we learn their different

properties and characteristics, we can then select the

right type of metal and use the proper method to

complete the job. Steelworkers primarily work with

iron and steel; however, we also must become familiar

with the nonferrous metals coming into use more and

more each da y. As St eelworkers, we must be able to

ident i f y var ious meta l s and to assoc ia te the i r

individual properties with their proper application or

use.

The primary objective of this chapter is to present

a detailed explanation of some of the properties of

different m eta ls an d to provide instruction on using

simple tests in establishing their identity.

METAL PROPERTIES

There is no simple definition of metal; however,

an y chemical element ha ving meta llic properties is

cla ssed as a meta l. Meta llic properties are defined

as luster, good thermal and electrical conductivity, and

the capab i l i ty o f be ing permanent ly shaped or

deformed at room temperature. Chemical elements

lacking these properties are classed as n onmetals. A

few elements, known as metalloids, sometimes behave

like a metal and at other times l ike a nonmetal . Some

examples of metal loids are as fol lows: carbon,

phosphorus, silicon, and sulfur.

An alloy is defined as a substan

properties that is composed of two

The elements used as alloying subs

metals or metalloids. The properties

from the properties of the pure meta l

make up the a lloy a nd this difference

usefulness of alloys. By combining

loids, manufacturers can develop al

part icular properties required for a g

Table 1-1 is a l ist of various e

symbols that compose metallic mat

Table 1-1.Symbols of Base Metals and


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Figure 1-1.Stress applied to a materiaI.

Very ra rely do Steelworkers work wit h elements

in their pure state. We primarily work with alloys and have

to understand their characteristics. The characteristicsof elements and alloys are explained in terms of

p h y s i c a l , c h e m i c a l , e l e c t r i c a l , a n d m e c h a n i c a l

properties. Physical properties relate to color, density,

weight, and heat conductivity . Chemical properties

involve the behavior of the metal when placed in

contact with the atmosphere, salt water, or other

substances. Electrical properties encompass the

electrical conductivity , resistance, and magnetic

qualities of the metal. The mechanical properties

re l a te to load-ca r ry ing ab i l i t y , wear res i s t ance ,

hardness, and elastici ty.

When selecting stock for a job, your main

concern is the mechanical properties of the metal.

The various properties of metals and alloys were

determined in the laboratories of manufacturers and

by var ious societ ies in teres ted in meta l lurgica ldevelopment. Cha rts presenting the properties of a

particular metal or al loy are available in many

commerci a l l y publ i shed re f e rence books . The

charts provide information on the melting point,

tensile strength, electrical conductivity, magnetic

properties, and other properties of a particular metal

or alloy. Simple tests can be conducted to determine

some of the properties of a metal ; however, we

norma l l y use a meta l t e s t on ly a s an a id f o r

identifying apiece of stock. Some of these methods

of testing are discussed lat er in this chapt er.

MECHANICAL PROPERTIES

Common types of stress are com

shear, torsion, impact, 1-2 or a com

stresses, such as fatigue. (See fig.

Compression stresses develop

when forces compress or crush the

that supports an overhead beam is i

the internal stresses that develop wit

compression.

Tension (or tensile) stresses

material is subject to a pulling load;using a w ire rope to li f t a load or w

guy to anchor an antenna. Tensile s

as resistance to longitudinal stress

measured in pounds per square inc

Shearing stresses occur within

external forces are applied along

opposite directions. Shearing for

material by sliding part of it in one

rest in the opposite direction.

Some materials are equally stron

tension, and shear. However, man

marked differences; for example, cu

maximum strength of 2,000 psi in

only 400 psi in tension. Carbon ste

strength of 56,000 psi in tension an

a maximum shear s trength o f o

therefore, when dealing with maxim

should always state the type of load

A material tha t is stressed repea

at a point considera bly below i ts ma

tension, compression, or shear. Fo


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Table 1-2.Mechanical Properties of Metals/Alloys

Strength Rockwell C number. On nonferrou

Strength is the property that enables a metal to resist

deformation under load. The ultimate strength is the

maximum strain a materia l can withstand . Tensi le

strengt h is a measurement of the resista nce to being

pulled apart when placed in a tension load.

Fatigue strength is the ability of material to resistvar ious kinds of rapidly changing st resses and is ex-

pressed by the magnitude of alternating stress for a

specified number of cycles.

Impa ct strength is the a bility of a met al to resist

suddenly a pplied loads an d is mea sured in foot-pounds

of force.

Hardness

Hardness is the property of a material to resist

permanent indentation. Because there are several meth-

ods of measuring hardness, the hardness of a material is

always specified in terms of the particular test that was

softer, a metal ball is used and the ha

by a Rockwell B number. To g

property of hardness, compare lead a

be scratched with a pointed woode

cannot because it is harder than lead

A full explanation of the variou

determine the hardness of a matercommercial books or books located in

Toughness

Toughness is the property t ha t en

withstand shock and to be deformed

Toughness may be considered as s trength a nd plast ici ty. Tab le 1-2s

some of the more common material

well as other properties.

Elasticity


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Plasticity

Plasticity is the ability of a material to deform

permanently without breaking or rupturing. This prop-

erty is t he opposite of strengt h. B y careful a lloying of

metals, th e combination of plasticity and strength is used

to manufacture large structural members. For example,

should a member of a bridge structure become over-

loaded, plasticity allows the overloaded member to flow

allowing the distribution of the load t o other pa rts of the

bridge structure.

Brittleness

Brittleness is the opposite of the property of plastic-

ity. A brittle metal is one that breaks or shatters before

it deforms. White cast iron and glass are good examples

of brittle material. Generally, brittle metals are high in

compressive strength but low in tensile strength. As an

example, you would not choose cast iron for fa bricat ing

support beams in a bridge.

Ductility and Malleability

Ductili ty is the property tha t enables a ma terial to

stretch, bend, or twist without cracking or breaking. This

property ma kes it possible for a mat erial to be draw n out

into a thin wire. In comparison, malleability is the

property that enables a material to deform by compres-

sive forces without developing defects. A malleable

material is one that can be stamped, hammered, forged,

pressed, or rolled into thin sheets.

CORROSION RESISTANCE

Corrosion resista nce, a lthough not a mecha nical

property, is importa nt in th e discussion of meta ls. Cor-

rosion resistance is the property of a metal that gives it

the ability to withstand attacks from atmospheric,

chemical, or electrochemical conditions. Corrosion,sometimes called oxidation, is illustrated by the rusting

of iron.

Ta ble 1-2 lists four mechanical properties and the

corrosion resistance of various metals or alloys. The first

metal or alloy in each column exhibits the best charac-

METAL TYPES

The metals that Steelworkers wo

into two general classifications: ferro

Ferrous metals are those composed p

iron alloys. Nonferrous metals are th

ma rily of some element or element

Nonferrous metals or alloys sometimamount of iron as a n a lloying elemen

FERROUS METALS

Ferrous metals include all form

alloys. A few examples include wrou

carbon steels, alloy steels, and tool s

als are iron-base a lloys w ith sma ll peand other elements added to achiev

ties. Normally, ferrous metals are m

rous metals are nonmagnetic.

Iron

Pur e iron r arely exists outside of

is produced by reducing iron ore to p

use of a blast furnace. From pig iron

of iron and steel are produced by the

of car bon an d a lloys. The following p

the different types of iron and stee

from iron ore.

PIG IRON. P ig iron is comp

iron, from 3%to 5%car bon, a nd v

other elements. Pig iron is compar

brittle; therefore, i t ha s a limited use

ninety percent produced is refined

Cast-iron pipe and some fittings an

factured from pig iron.

WROUGHT IRON. Wrought

pig iron with some slag mixed in du

Almost pure iron, the presence of sl

iron to resist corrosion and oxidatanalyses of wrought iron and mild s

the same. The difference comes fr

contr olled during the ma nufactur ing

iron can be gas and arc welded, mac

easily formed; however, i t has a lo

low-fatigue strength


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hardness . A mal leable cas t i ron is produced through a eas ily as the low-carbon s tee ls . They

prolonged a nnea ling process. hooks, a xles, sha ft s, set screw s, a nd s

INGOT IRON. Ingot iron is a commercially pure

iron (99.85% iron) th at is easily formed a nd possesses

good ductilit y a nd corrosion resist a nce. The chemical

an alysis a nd properties of this iron and the lowest carbon

steel are practically the same. The lowest carbon steel,

known as dead-soft, has about 0.06%more carbon than

ingot iron. In iron the carbon content is considered an

impurity a nd in st eel it is considered a n a lloying ele-

ment. The primary use for ingot iron is for galvanized

and enameled sheet.

Steel

Of all the different metals and materials that we use

in our trade, steel is by far the most important. When

steel was developed, it revolutionized the American iron

industry. With it came skyscrapers, stronger and longer

bridges, and railroad tracks that did not collapse. Steel

is ma nufactured from pig iron by decreasing t he a mountof carbon and other impurities and adding specific

amounts of alloying elements.

Do not confuse steel with the two general classes of

iron: cast iron (great er tha n 2% carbon) a nd pure iron

(less than 0.15%carbon). In steel manufacturing, con-

trolled amounts of alloying elements are added during

the molten stage to produce the desired composition.

The composition of a steel is determined by its applica-tion and the specifications that were developed by the

following: American Society for Testing and Materials

(ASTM), the American Society of Mechanical Engi-

neers (ASME), the Society of Automotive Engineers

(SAE), and the American Iron and Steel Institute (AISI).

Car bon steel is a term applied to a broad range of

steel that falls between the commercially pure ingot iron

an d the cast irons. This ra nge of ca rbon steel ma y beclassified into four groups:

HIGH-CARBON STEEL/VE

BON STEEL. Steel in these class

heat treatment and can be welded. W

cial electrodes must be used along w

stress-relieving procedures to prevent

ar eas. These steels are u sed for dies

tools, ra ilroad car w heels, chisels, kn

LOW-ALLOY, HIGH-STR

PERED STRUCTURAL STEEL.

carbon steel, containing specific

alloying elements, that is quenched aa yield strength of greater than 50,0

str engths of 70,000 to 120,000 psi. St

made from these high-strength steels

cross-sectional a reas tha n common

and sti l l have equal or greater s tren

these steels are normally more corros

resistan t. High-strengt h st eels a re

specifications.

NOTE: This type of steel is m

low-ca rbon steels. Shear ing ma chin

steel must ha ve twice the capacity tha

low-carbon steels.

STAINLESS STEEL. This ty

sified by the American Iron and Ste

into two general series named the 2

400 series. Each series includes sevwith different characteristics.

The 200-300 series of sta inless

AUSTENITIC. This type of steel

ductile in the as-welded condition; th

for welding an d requires no a nnea l

atmospheric conditions. The most w

steel in this series are the 302 and 3

monly ca lled 18-8 beca use t hey a re

chromium a nd 8% nickel. The chromLow-Carbon Steel . . . . . . . . 0.05%to 0.30%carbon ar e the most widely used a nd a re norm

Medium-Ca rbon S teel . . . . . . 0.30%t o 0.45%car bonThe 400 series of steel is su bdiv

High -Ca rbon St eel . . . . . . . . 0.45%t o 0.75%ca rbon their crystalline structure into two ge


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and frequently used for decorative trim and equipment

subjected to high pressures and temperatures.

Martensitic Chromium. These steels ar e ma g-

netic and are readily hardened by heat treatment. They

conta in 12% to 18% chromium, 0.15% to 1.2% carbon,

a nd u p to 2.5%nickel. This gr oup is used w here high

strength, corrosion resista nce, a nd ductility a re required.

ALLOY STEELS. Steels that derive their prop-

erties primarily from the presence of some alloying

element other than carbon are called ALLOYS or AL-

LOY STEELS. Note, however, that alloy steels always

contain traces of other elements. Among the more com-

mon alloying elements are nickel, chromium, vana-

dium, silicon, and tungsten. One or more of these

elements may be added to the steel during the manufac-

tur ing process to produce the desired cha ra cteristics.

Alloy steels may be produced in structural sections,

sheets, plates, a nd ba rs for use in the a s-rolled condi-

tion. Better physical properties are obtained with these

steels than are possible with hot-rolled carbon steels.

These alloys a re used in str uctures where t he strength of

material is especially important. Bridge members, rail-road ca rs, dump bodies, dozer blades, and crane booms

a re ma de from alloy steel. Some of the common alloy

steels are briefly described in the paragraphs below.

Nickel Steels. These steels contain from 3.5%

nickel to 5% nickel. The nickel increases t he str ength

and toughness of these steels. Nickel steel containing

more than 5%nickel has an increased resistance to

corrosion and scale. Nickel steel is used in the manufac-

ture of aircraft parts, such as propellers and airframe

support members.

Chromium Steels. These steels have chromium

added to improve hardening a bility, wea r resistan ce, an d

strength. These steels contain between 0.20%to 0.75%

chromium and 0.45%carbon or more. Some of these

steels are so highly resistant to wear that they are used

for t he races and ba lls in a ntifriction bear ings. Chro-

mium steels are highly resistant to corrosion and t o

scale.

Chrome Vanadium Steel. This steel has the

maximum a mount of s trength with the least amount of

h S l f h f % %

to cut after it becomes red-hot. A goo

conta ins from 13%t o 19%tungste

dium, 3%t o 5%chromium, a nd 0.6

Because this alloy is expensive to

largely restricted to the ma nufacture

milling cutters, and similar cutting t

Molybdenum. This is often u

agent for steel in combination wi

nickel. The molybdenum adds tough

can be used in place of tungst en to

grades of high-speed steel and in ca

high-pressure tubing.

Manganese Steels. The am o

used depends upon the properties des

product. Small amounts of mangane

free-machining steels. Larger amo

a nd 10%) produce a somew ha t brit t

la rger a mount s (11%t o 14%) prod

tough and very resistant to wear afte

ment .

NONFERROUS METALS

Nonferrous metals contain eith

insignificant amounts used as a n a lloy

common nonferrous metals Steelwor

as follows: copper, brass, bronze, co

lead, zinc, tin, aluminum, and Dural

NOTE: These metals are nonma

Copper

This metal and its a lloys ha ve m

erties. Among th e commercial meta

most popular. Copper is ductile, mal

strong, wear resistant, machinable,

rosion resista nt. I t also has high-tens

strength, and thermal and electrical

per is one of the easier metals to w ork

because it easily becomes work-harde

condition can be remedied by heatin


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True Brass sinks or protect bench tops where a la

is used. Lead-lined pipes are used in

This is an alloy of copper and zinc. Additional corrosive chemicals. Frequently, lead

elements, such as aluminum, lead, tin, iron, manganese, form to increase its low-tensile stre

or phosphorus, are added to give the alloy specific tin, lead produces a soft solder. Wh

properties. Naval rolled brass (Tobin bronze) contains alloys, lead improves their machinababout 60% copper, 39%zinc, a nd 0.75% tin. This bra ss

is highly corrosion-resistant and is practically impurity

free. CAUTION

Bra ss sheets a nd s tr ips are a vai lable in several

gra des: soft, 1/4 ha rd, 1/2 ha rd, full h a rd, a nd s pring When working with lead, y

g ra d es . Ha rd nes s i s crea te d by the proces s of cold rol l- proper preca u t ions beca us e the d

ing. All grades of brass can be softened by annealing at vapors from it ar e highly poison

a temperature of 550F to 600F then allowing it to coolby itself without quenching. Overheating can destroy

the zinc in the alloy. Zinc

Bronze

B ronze is a combinat ion of 84%copper an d 16%t in

and was the best metal available before steel-making

techniques were developed. Many complex bronze al-

loys, containing such elements as zinc, lead, iron, alu-

minum, silicon, and phosphorus, a re now ava ilable.

Today, the name bronze is applied to any copper-based

alloy that looks like bronze. In many cases, there is no

real distinction between the composition of bronze and

that of brass .

Copper-Nickel Alloys

Nickel is used in t hese alloys t o make th em strong,

tough, and resistant to wear and corrosion. Because of

their high resistance to corrosion, copper nickel alloys,

conta ining 70% copper a nd 30% nickel or 90% copper

and 10%nickel, are used for saltwater piping systems.

Small storage tanks and hot-water reservoirs are con-

You often see zinc used on iron o

of a protective coating called galvan

used in soldering fluxes, die castings

making brass and bronze.

Tin

Tin has ma ny importa nt uses as

a lloyed wit h lead t o produce softer

copper to produce bronze. Tin-based

resistance to corrosion, low-fat igue st

pressive strength that accommodate

loads. Tin, like lead, has a good resiand has the added advantage of not

however, w hen subjected t o extrem

tures, it h as a tendency to decompos

Aluminum

strutted of a copper-nickel alloy that is available in sheetThis metal is easy to work wit

form. Copper-nickel alloys should be joined by metal-appearance. Aluminum is light in wearc welding or by brazing.strength per unit w eight . A disadv

Leadtensile strength is only one third of t

fifth of that of annealed mild steel.

A hea vy meta l tha t w eighs about 710 pounds per

cubic foot. In spite of its weight, lead is soft and malle-

Aluminum alloys usually conta in

minum. The addition of silicon, ma


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Table 1-3.Surface Colors of Some Common Metals

Duralumin Monel

One of the first of the strong structural aluminum

alloys developed is called Duralumin. With the devel-

opment of a variety of different wrought-aluminum

alloys, a num bering system wa s a dopted. The digits

indicat e the ma jor a lloying element a nd t he cold-worked

or heat-treated condition of the metal. The alloy, origi-nally called Duralumin, is now classified in the metal

working indust ries a s 2017-T. The lett er T indicates tha t

the metal is heat-treated.

Alclad

Monel is an alloy in which n

element. It contains from 64%to 68%

copper, and small percentages of ir

cobalt. Monel is harder and stronge

or copper and has high ductility. It

steel in appearance and has many ostrength, combined with a high resi

make Monel an a cceptable substitute

where corrosion resistan ce is the prim

bolts, screws, and various fittings a

This a lloy can be w orked cold and

welded If worked in the tempera t


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comparable to heat-treated steel. K-monel is used for

instrument parts that must resist corrosion.

Inconel

This high-nickel alloy is often used in the exhaust

systems of aircraft engines. Inconel is composed of

78.5% nickel, 14% chromium, 6.5% iron, a nd 1% of

other elements. It offers good resistance to corrosion and

retains its strength at high-operating temperatures.

METAL IDENTIFICATION

Many methods are used to identify a piece of metal.

Identification is necessary when selecting a metal for

use in fabrication or in determining its weldability.

Some common m ethods used for field identification a re

surface appearance, spark test, chip test, and the use of

a magnet.

SURFACE APPEARANCE

Sometimes it is possible to identify metals by their

surface appearance. Table 1-3 indicates the surface col-

ors of some of the more common metals. Referring to

the table, you can see that the outside appearance of a

metal helps to identify and classify metal. Newly frac-

tur ed or freshly filed surfaces offer a dditional clues.A surface examination does not always provide

enough information for identification but should give us

enough information to place the metal into a class. The

color of the meta l an d th e distinctive ma rks left from

manufacturing help in determining the identity of the

metal . Cast iron and malleable iron usually show evi-

dence of the sand mold. Low-carbon steel often shows

forging marks, and high-carbon steel shows either forg-ing or rolling marks. Feeling the surface may provide

a nother clue. Sta inless steel is slightly r ough in the

unfinished state, and the surfaces of wrought iron, cop-

per, brass, bronze, nickel, and Monel are smooth. Lead

also is smooth but has a velvety appearance.

Figure 1-2.Terms used in sp

SPARK TEST

The spark test is made by hold

material against an abrasive wheel.

ing the spark stream, an experience

identify the metals with considerable

is fast, economical, convenient,

plished, and there is no requiremen

ment. We can use this test for identi

from scrap. Identification of scrap is

ta nt when selecting material for ca

hea t t r ea t ment .

When y ou hold a piece of iron

with a high-speed abrasive wheel, sm

metal are torn loose so rapidly that th

As th ese glowing bits of meta l lea

follow a path (trajectory) called th

carrier line is easily followed with

when observed against a dark backg

The spar ks given off, or the la ck

identif ication of the metal. The l

strea m, the color, a nd the form of theyou should look for. Figure 1-2 illustr

in referring to various basic spark

spark testing.

Steels having the same carbon c

alloying elements are difficult to id


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by tiny blocks of brilliant white light. Silicon suppresses

the carbon burst even more than nickel. When silicon is

present, t he carrier line usually ends abruptly in a white

f lash of light.

Spark testing may be done with either a portable or

stationary grinder. In either case, the speed on the outer

rim of the wheel should not be less than 4,500 feet per

minute. The abrasive wheel should be rather coarse,

very hard, and kept clean to produce a true spark

To conduct a spark test on an abrasive wheel, hold

the piece of metal on the wheel in a position that allows

the spark st ream t o cross your line of vision. By t rial a nd

error, you soon discover what pressure is needed to get

a stream of the proper length without reducing the speedof the grinder. Excessive pressure increases the t em-

perature of the spark stream. This, in turn, increases the

temperature of the burst and gives the appearance of a

higher carbon content than actually is present. When

ma king the test , wa tch a point a bout one third of the

distance from the tail end of the spark stream. Watch

only those sparks that cross your line of vision and try

to forma mental image of the individual spark. Fix thisspark image in your mind a nd th en examine the w hole

spark picture.

While on the subject of abrasive wheels, it is a good

idea to discuss some of the safety precautions associated

with this tool.

Never use an abra sive wh eel tha t is cracked or

out of balance because the vibration causes the wheel toshatter. When an abrasive wheel shatters, i t can be

disastrous for personnel standing in line with the wheel.

Always check the wheel for secure mounting andcracks before putting it to use. When you install a new

wh eel on a grinder, be sure tha t it is t he correct size.

Remember, as you increase the wheel radius, the periph-

eral speed a t t he rim a lso increases, even th ough the

driving motor rpm remains the same. Thus, if you should

use an oversized wheel, there is a distinct danger the

peripheral speed (and consequent centrifugal force) can

become so great that the wheel may f ly apart . Use

wheels that are designed for a specific rpm. Guards are

l d d h l h ld

Never overload a grinder or sure aga inst t he wh eel, unless i t is

withstand such use.

Always wear appropriate safetshield while using the grinder. Ensu

(the device that helps the operator

adjusted to the minimum clearance f

the work across the entire face of the

grooving a nd t o minimize wheel d

prolongs the life of the wheel.

Keep your fingers clear of thand do not allow rags or clothing to

in the wheel.

Do not wear gloves while wheel.

Never hold metal with tongs

Never grind n onferrous mettended for ferrous metals because su

pores of th e abra sive mat erial. Th

may cause i t to become unbalanced

Grinding wheels require freing. Dressing is the term used to des

cleaning the periphery. This cleanin

abra sive gra ins and smooths the su

the grooves. The wheel dresser sho

used for dressing grinding wheels on

grinders. For more information on g

should consult chapter 5 of NAV

(Tools and T heir U ses).

Referring now to figure 1-4,

carbon steel (view A), the spark s

inches long and the volume is m

high-carbon steel (view B), the strea

55 inches) and the volume larger. Th

may occur at any place in low-carbo


11/14


12/14

Table 1-4.Metal Identification by Chip Test

and in high-carbon steel, they a re small a nd repeating. these metals must be distinguished fr

Both metals produce a spark stream white in color.

Gray cast iron (view C) produces a stream of sparks

b t 25 i h i l gth Th kl ll d

some other method.

St ainless steel (view E ) produce

about 50 inches in length moderate


13/14

One way to become proficient in spark testing fer-

rous metals is to gather an assortment of samples of

known metals and test them. Make all of the samples

about the same size and shape so their identities are not

revealed simply by the size or shape. Number each

sample and prepare a list of names and corresponding

numbers. Then, without looking at the number of the

sample, spark test one sample at a time, calling out its

name to someone assigned to check it against the names

and numbers on the list. Repeating this process gives

you some of th e experience you n eed to become profi-

cient in identifying individual samples.

CHIP TEST

from small, broken fragments to a co

chip may have smooth, sharp edge

grained or fine-grained; or it may h

The size of the chip is important in id

The ease with which the chipping c

should also be considered. The in

table 1-4can help you identify var

chip test.

MAGNETIC TEST

The use of a magnet is another

in the general identification of meta

ferrous meta ls, being iron-based aAnother simple test used to identify an unknown

piece of metal is the chip test. The chip testis made by

removing a small amount of material from the test piece

with a sharp, cold chisel. The material removed varies

magnetic, and nonferrous metals are

test is not 100-percent accurate bec

steels are nonmagnetic. In this in

substitute for experience.


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properties+uses-of-metals

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