29
OF ENGINEERING FOEMULÆ.
Admibalty Tests for Steel—continued.
allowed for rolling in plates of half an inch in thickness and
upwards, and 10 per cent, in thinner plates.
Ihese weights may be ascertained by weighing as much as
10 tons at a time.
TESTS FOK ANGLE, BULB, OR BAR STEEL.
The whole of the steel to stand a tensile strain of 26 tons
to the square inch, and not to exceed 30 tons to the square
meh. 1
Also to stand the extension and tempering tests described
for plates.
All the cross ends to be cut off. One bar is to be taken
for testing from every invoice, providing the number of bars
does not exceed 50; if above that number, one for every
additional 50, or portion of 50.
Lloyd’s Tests fok Steel used in Ship-building.
Strips cut lengthwise or crosswise of the plate, and also
angle and bulb steel, to have an ultimate tensile strength of
not less than 27, and not exceeding 31 tons per square inch of
section, with an elongation corresponding to 20 per cent, on
a length of 8 inches before fracture.
Strips cut from the plate, angle or bulb steel to be heated
to a low cherry-red, and cooled in water of 82° Fahrenheit,
must stand bending double round a curve of which the dia-
meter is not more than three times the thickness of the
plates tested.
No reduction will be allowed in the sizes of rivets from
those which would be required by the Rules for the vessels if
built of iron.
In other respects the Rules for the construction of iron
ships will apply equally to ships built of steel.