ble for the foundry to produce as much as 950 tons of certain kinds of castings. Therefore, the minimum gen-
.ral overhead expense to be used when calculating the cost of a casting, is in this example $45,342.00 divided
3y 050 or $47.73 per net ton of good castings.
The above procedure illustrates the manner in which each foundry should use its own average cost data
for establishing the cost of steel and the overhead rates to be used for calculating the costs of castings made
from individual patterns.
COST OF INDIVIDUAL CASTINGS
Knowledge of average monthly costs of making castings is not enough, and it is essential that further
analysis of the business be made by studying the costs of making castings from specific patterns. Without the
nformation obtained from job costs, the foundryman has no guide to aid him in keeping the costs of making
pecific castings at a minimum or in eliminating from his business those jobs that cannot be made at a profit.
It is not a complicated procedure to get the actual and estimated costs of castings made from individual
patterns. A full explanation of it is given here.
The following basic data must be obtained for each casting whoses cost of production is to be deter-
nined: shipping weight, weight of heads and gates, weight or number of defective castings, molding direct
bor, core direct labor, and cleaning direct labor. The molding, core, and cleaning direct labor are defined
in the standard classification of accounts given on page 7, and it is very important that these direct labor data
he correctly determined. The shipping weight, weight of heads and gates, and weight or number of defective
-astings, are the data necessary for determining the yield and consequently the cost of steel in the casting as
explained on page 17. The molding direct labor, core direct labor, and cleaning direct labor for the specific
casting, are the data required for determining the indirect and overhead expense applicable to the casting by
1sing the overhead rates explained on page 22.
The method of calculating the cost of a casting or castings made from a specific pattern is illustrated
on the page following which contains a sample job cost form. All figures in this example are assumed. The
overhead rates and cost of steel are taken from the assumed data on the Monthly Summary of Cost of Produc-
on of Good Castings on page 18, and they are described in the section beginning on page 17.
In the case of alloy steel, an addition must be made to the cost of the regular carbon steel, to cover the
axtra cost of the alloys used.
If the amount of defective castings is added in the form of a percentage when determining the cost of
;astings made from a specific pattern, it should always be stated as a percentage of the good castings. This
sercentage should never be a percentage of the total castings, meaning the sum of the good and the defective
~astings.
The yield for the castings described on the Cost Record following, is obtained by using the following
‘ormula described on page 17:
Gx [00—(S+L+B)]
Per cent. yield = ——m———————— —
G LDL H
The figures for S, L, and B, in this-formula are obtained from the Monthly Summary of Cost of Production
»f Good Castings, and using the assumed figures on page 19, S is 3 percent, L, is 10 percent, and B is 0.3 per-
sent. Therefore. the formula for yield is reduced to the following in this instance:
86. G
Per cent, yield = _Se7 X ©
G 4+ DL H
Each foundry must establish this simple formula by using its own data for the terms S, I, and B, and it is
asually desirable to insert it on the Cost Record for quick reference and use in calculating the vield for cast-
ings from a specific pattern.