Tensile tests
56.—(1)  The tensile breaking strength of steel plates for shells and girders, determined from standard test-pieces, shall be ordinarily between the limits of 28 tons and 35 tons per square inch, but a range of not more than 4 tons per square inch shall be permitted in any one case.
(2)  For plates intended for flanging or welding, and for combustion chambers and furnaces, the tensile breaking strength shall be between the limits of 26 tons and 30 tons per square inch.
(3)  The elongation, measured on a standard test-piece having a gauge length of 8 inches, shall be not less than 20% for material of 3/8 inch in thickness and upwards required to have a tensile breaking strength between the limits of 28 tons and 35 tons per square inch; and not less than 23% for material of 3/8 inch in thickness and upwards required to have a tensile breaking strength between the limits of 26 tons and 30 tons per square inch.
For material under 3/8 inch in thickness the elongation may be 3%, but not more than 3%, below the above named elongations.