Agricultural Mechanics
Fundamentals &
Applications
UNIT 19—Figuring a Bill
of Materials (BOM)
Bill of Materials
• Define as a list and description of all
the materials to be used in
constructing a project.
Components
• Bill of materials should include:
–
–
–
–
–
–
–
–
Item or part name
Number of pieces
Type of material
Size of pieces
Description of parts
Total feet
Unit cost
Cost
Tips
• Calculate:
- number of pieces
- total footage
- type of wood, etc.
- individual prices
- total cost
• Be sure to calculate lumber for the length
that is to be purchased—not just the
length to be used for the project.
Calculating Board Feet
• For small lumber:
BF = Thickness (in)  Width (in)  Length (in)
144
Or: BF = T''  W''  L''
144
• For large lumber:
BF = T''  W''  L'
12
Pricing
• Rough Lumber from sawmill is sold by
per thousand board feet.
• Wood products that are sold in
sheets are sold by the panel or by
the square foot.
• Retail stores sell lumber by linear
measurements.
Standard Abbreviations
“ or in = inch
‘ or ft = foot
yd = yard
mi = mile
ea = each
@ = at
N/A = not applicable
pt = pint
lb = pound
d = penny(nails)
NC= Nat’l coarse
NF=Nat’l fine
NPT=Nat’l pipe
Standard Abbreviations
LF = linear foot
BF = board foot
S1S = surface 1 side
S2S = surface 2 sides
S3S = surface 3 sides
S4S = surface 4 sides
No. /# = number
in² = square inch
ft² = square foot
yd² = square yard
Standard Abbreviations
Square = 10’ X 10’ or 100 square feet
NC = national coarse threads
NF = national fine threads
NPT = national pipe threads
d = penny (nails)
lb = pounds
Cwt = hundredweight (100 lbs)
Lumber
• Available in 6’, 8’, 10’, 12’, 14’, 16’,
– Special orders for 18’ & 20’
– Widths
•
•
•
•
1x6
1x8
1x10
1x12
2x4
2x6
2x8
2x10
2x12
4x6
Plywood
• Interior and Exterior grades
– Available in 4’ x 8’ sheet
– Thickness – ¼”, 3/8”, ½”, 5/8”, ¾” 1”
Structural Steel
• Standard Length – 20feet
– Flat iron – thickness –
1/8,3/16,1/4,5/16,3/8,1/2
– Width – ½, ¾,, 1, 1-1/2, 2, 3, 4, 5 inch
– Angle iron – thickness – same as flat iron
– Width – 1/2x1/2; 3/4x3/4; 1x1; 1-1/2x1-1/2;
2x2; extends to 4x4
– Round –Hot Rolled, Cold Rolled or Tool Steel
– Size in diameter = ¼, 5/16,3/8,3/4,1 to 3”
Steel Pipe
• Standard length = 21 feet
• Black & galvanized
• Lengths
– ¼, 3/8, ½, ¾, 1 up to 3 inches
Important Terms
• Item—a separate object.
• Rounded Up—when rounding
numbers, round to the next highest
number.
• Tongue and Groove Lumber—lumber
with a tonguelike edge sticking out on
one side and a groove cut into the
other.
Terms Cont.
• Galvanize—coat a metal with zinc.
• Cadmium—used for rust-resistant
plating of steel products.
• Board Foot—an amount of wood equal
to a board 1'' thick, 1' wide, and 1'
long.