Page:Sheet Metal Drafting.djvu/131

Rh handles are attached to the barrel and it is then ready for final inspection.

54. Related Mathematics on Ash Barrel.—In order to estimate the cost of the article to be made by quantity production methods, each item must be considered separately.

Sample Problem.—Figure the cost of stock entering into the manufacture of 500 ash barrels such as shown in Fig. 157.

''Item 1. Cost of 500 Body Blanks.'' Fig. 159.
 * Size of sheets 24"×120", No. 24 gage
 * Area of sheet 20 sq. ft.
 * Number of sheets required—250 (2 bodies from each sheet)
 * Total area of 500 body blanks 250×20 = 5000 sq. ft.
 * Weight of No. 24 galv. steel per sq. ft. =1.156 lb.
 * Total weight of bodies, 1 . 156×5000 = 5780 lb.
 * Cost of 500 bodies at 8.5¢ per lb. = $491.30

''Item 2. Cost of 500 Bottom Blanks.''
 * Size of blank = 19 $$\scriptstyle\frac{43}{64}$$" diameter
 * Size of sheet required, 24"×120', No. 20 gage
 * Number of blanks from each sheet, 6
 * Number of sheets required, 500÷6 = 84
 * Total area of each sheet = 20 sq. ft.
 * Total area of 84 sheets (84×20)=1680
 * Weight of No. 20 galv. steel per sq. ft.=1.656 lb.
 * Total weight of metal required (1680×1.656)=2782 lb.
 * Cost of 500 bottoms at 8.5¢ per lb.=$236.47

''Item 3. Cost of 4000 Single Rib Slats.''
 * Size of blank, 24"×2⅞", No. 24 gage
 * Size of sheet required, 24"×120"
 * Number of blanks from each sheet, 41
 * Number of sheets required, 4000÷41=98 sheets
 * Weight per sheet, 23. 12 lb.
 * Weight of 98 sheets, 98×23.12=2265.76 lb.
 * Cost of 4000 metal slats at 8.5¢ per lb. =$192.59

''Item 4. Cost of Hoops.''
 * Length of upper hoop=56.07"
 * Length of lower hoop=55.95"
 * Combined length of upper and lower hoops=112.02"
 * Total length of 500 upper and 500 lower hoops,
 * $$\scriptstyle \frac{(500 \times 112'')}{12}=4666$$ ft.
 * Weight of 4666 ft. at 1.195 lb. per ft.=5575.87 lb.
 * Plus 5 per cent for waste=5854.66 lb.
 * Total cost of hoops at 11¼¢ per lb.=$658.65