The following Table shows the tensile strength, contraction of area and elongation after fracture, ascertained by experiments upon some of the more important descriptions of iron found in the market.

Average Tensile Strength And Ductility Of Iron Plates And Bars Made By Several Noted Manufacturers

Manufacturers and Description of Iron.

Tensile strength per square inch of original section.

Contraction of area fractured.

Ultimate elongation.

Round Oak Iron Works (see p. 296) -

Tons.

Per cent.

Per cent in 10 inches.

L.W.R.O. bars.....

24.94 to

48.2 to

28.8

26.57

44

27.5

Best bars ......

24.67

45.3

25..

Best best bars .....

23.35

45.2

297

Best best best bars ....

23.60

46.9

30.7

Best rivet iron bars ....

24.75

457

26.6

Best best best rivet iron bars

24.26

47.2

27.4

Shelton Iron & Steel Co., Stoke-on-Trent -

in 12 inches.

Best boiler plates, 1/2 in. thick, lengthways

22.3

10.3

7.3

„ „ „ crossways

18.7

4.6

4.2

Best best boiler plates, 7/16 -in. thick, „ „ lengthways

23.6

16.2

8.8

„ ,, „ crossways

20.6

10.4

5.2

Rivet iron ......

25.0

40.0

27.0

Angle iron .....

26.5

34.1

27.0

N. Hingley and Sons, Dudley - Netherton crown best bar iron..

22.6 to

45.0 to

30.0

23.8

35.0

24.0

,, ,, ,, rivet iron

23.5

50.0

20.0

1 Extracted from Tables in Hutton's Practical Engineer's Handbook.

Table Giving The Tensile Strength And Ductility Of Various Descriptions Of Malleable Iron. From Mr. Kirkaldy's Experiments

District.

Names of Makers or Works and Brands.

Description.

Tearing weight per sq. inch of original section, in tons.

Contraction of area fractured.

Ultimate elongation or tensile set after fracture.

Rolled Bars.

Per cent

Per cent

Yorkshire .

Lowmoor

Rolled Bars, round, 1" diameter

27.59

53.1

26.5

Do. .

Bowling

Do.

27.86

45.3

24.4

Do. .

Farnley

Do.

28.07

50.6

25.6

Staffordshire

J. Bradley & Co., L circle (charcoal)

Do.

25.54

60.9

30.2

Do.

Do. B.B. scrap

Do.

26.5

52.0

26.6

Do.

Do. S.C.Table Giving The Tensile Strength And Ductility Of 300206

Do. 7/8"dia.

27.78

36.2

22.2

Do.

Table Giving The Tensile Strength And Ductility Of 300207

J. Bagnall, J.B. .

Do. 11/4" do.

24.55

270

17.3

Scotland .

Govan, Ex. B. Best

Do. l"do.

26.39

40.0

223

Do. .

Do. B. Best .

Do.

28.05

28.9

19.1

Do. .

Do. # .

Do.

2653

25..1

16.4

Do. .

Glasgow, B. Best.

Do.

26.29

39.6

23.2

Wales

Ystalyfera (puddled)

Flat strips.

17.20

2.4

2.0

Rivet Iron.

Diameter.

Yorkshire .

Lowmoor

Round. 11/16"

26.82

52.2

20.5

Do. .

Bradley & Co., S.C.

Table Giving The Tensile Strength And Ductility Of 300208

Do. 3/4

25.32

49.5

22.5

Lancashire

Ulverstone, Rivet Best .

Do. 3/4

24.00

48.6

21.6

Staffordshire

Thorneycroft & Co., TNS

Do. 13/16"

26.46

40.4

22.4

Do.

Lord Ward, L Table Giving The Tensile Strength And Ductility Of 300209 W. . R. 0.

Do. 11/16"

26.69

37.6

18.6

Scotland .

Glasgow, Best Rivet

Do. |"

25.49

40.7

23.7

Iron Plates.

Thickness.

Yorkshire .

Lowmoor

L. 5/16"

23.21

19-7

13.2

C 5/16"

22.55

12.1

9.3

Do. .

Farnley

L. 3/8"

25.00

17.8

14.1

C. |"

20.63

13.2

7.6

Do. .

Bowling

l. 3/8

23 32

15.3

11.6

C. 3/8"

2073

6.9

5.9

Staffordshire

Bradley & Co., S.C.

Table Giving The Tensile Strength And Ductility Of 300210

L. 1/2"

24.92

17.2

12.5

C. 1/2

22.52

9.0

5.5

Do.

Thorneycroft, Best Best

L. 15/16"

24.48

125

11.2

C 15/16"

20.35

4.6

4.6

Do.

Lloyds, Foster, & Co., Best

L. 6/16" to 7/16"

20..7

8.7

5.3

C. Do.

1992

6.9

4.6

North of England

Consett, Best Best

L. 3/4

22.88

13.1

8.9

C. |"

20..85

10.2

6.4

Scotland .

Glasgow, Best Best

L. 1/4" to 3/4"

23.84

10.6

9.0

C. Do.

18.65

3.7

2.6

Angle Iron.

Yorkshire .

Farnley_

Thickness 9/16"

27.34

41.4

20.9

Staffordshire

Albion Table Giving The Tensile Strength And Ductility Of 300211 Best .

Do. 5/8"

25.07

19.1

14.0

Do.

Do. Best

Do. 1"

23.28

22.8

14.1

Do.

Eagle ....

Do. 21/32"

22.34

15.3

8.8

Do. Best Best .

24.42

23.4

13.7

Durham .

Consett

do. 9/16"

22.68

11.7

5.8

Do. .

Do. Best Best.

Do. 1/2"

23.90

18.3

12.6

Scotland .

Glasgow, Best scrap

Do. |"

25.04

20.1

15.0

Do. .

Do. Best Best .

Do. |"

24.78

11.0

8.5

l Kirkaldy's Experiments on Wrought Iron and Steel, Tables G, J, K. In these and all the other selections from Mr. Kirkaldy's experiments the stresses given by him in lbs. have been reduced to tons.

L. signifies lengthways - in the direction of the grain; C. crossways - across the grain.

From the results above recorded, it will be seen that the average of ordinary qualities of bar iron is nearly 20 per cent stronger than that of the same qualities of plate iron, and its elongation under a given stress is 21/2 times as great; also that plate iron has a greater strength in the direction of the fibre or grain than across the grain, the difference being on the average about 10 per cent.

The Elastic Limit Of A Few Different Classes Of Iron Is Shown In The Following Table (See Also P. 331)

Description of Ikon.

Elastic limit in tension, tons per square inch.

Breaking tensile stress per square inch.

Elongation in

10 inches per cent.

Bowling iron 1 with grain .

12.6

20.9

19.8

,, „ across grain .

11.1

18.4

7'5

Barrow B.B.H.1 ....

14.5

25.4

22.3

Cleveland 2 3/8inch and 1/2inch plates -

in 8 inches.

With grain . . . .

137

21.0

7.5

Across grain ..

18.2

3.0

Belgian joists 3 .....

16.9 to

22.4 to

15.4

20.9

in 3 inches.

Wrought iron from crank shaft .

13.3

14.18

4.0

The Crushing Strength of wrought iron varies in different specimens with the hardness of the iron.

" Ordinary wrought iron is completely crushed, i.e. bulged, with a pressure of from 16 to 20 tons per square inch." 4

The best soft wrought iron begins to bulge sensibly with about 12 tons per square inch.5

The Shearing Strength of wrought iron has been proved by experiment to be equal to the tensile strength of the material.