Full resolution (JPEG) - On this page / på denna sida - Weights and Measures - To calculate weights of casting from weight of pattern - Weight of a bar of rough iron of any shape of cross section - To calculate the weight of sheet iron of any thickness - To calculate weight of metals not given in the tables
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WEIGHTS AND MEASURES. 141
To Calculate Weight of Casting from Weight of Pattern.
When pattern is made from pine and no nails used, the
rule is : Multiply the weight of the pattern by 17 and the prod-
uct is the weight of the castings.
When nails are used in the pattern, multiply its weight by
a little less, probably 15 or 16.
When the pattern has core prints, their weight must be
calculated and also the weight of what there is to be cored out
in the casting, which must all be deducted. This mode of cal-
culating the weight of castings is, of course, only approxima-
tion, but it is frequently very useful.
Weight of an Iron Bar of any Shape of Cross Section.
A wrought iron bar of 1 square inch area of cross section
and one yard long weighs 10 pounds. Therefore, the weight of
wrought iron bars of any shape, as, for instance, railroad rails,
X beams, etc., may very conveniently be obtained by first mak-
ing a correct, full size drawing of the cross section and measur-
ing its area by a planimeter, which gives the area in square
inches. Multiply this area by 10 and the product is the weight
in pounds per yard; or multiply the area by 3.33 and the product
is the weight in pounds per foot.
To Calculate Weight of Sheet Iron of any Thickness.
One square foot of wrought iron, 1 inch thick, weighs very
nearly 40 pounds (40.2 pounds) and one square foot ¥y, which
is Tftb thick, weighs 1 pound. Therefore, a practical rule for
quick calculation of the weight of sheet iron is: Divide the
thickness of the iron as measured by a micrometer calliper in
thousandths of inches by 25, and the quotient is the weight in
pounds per square foot.
To Calculate the Weight of Metals Not Given in the Tables.
Find the weight of wrought iron, and multiply by the fol-
lowing constants
:
Weight of wrought iron X 0.928 = cast iron.
X 1.014 = steel.
" X 0.918 = zinc.
" " "
"X 1.144 = copper.
" X 1.468 = lead.
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