This section is from the book "Notes On Building Construction", by Henry Fidler. Also available from Amazon: Notes on building construction.
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.
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 |
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.
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. | Do. 7/8"dia. | 27.78 | 36.2 | 22.2 |
Do. | 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. | 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 | Do. 11/16" | 26.69 | 37.6 | 18.6 |
Scotland . | Glasgow, Best Rivet | Do. |" | 25.49 | 40.7 | 23.7 |
Iron Plates. | |||||
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. | 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 | 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.
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.
 
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