Agricultural Agricultural MechanicsMechanics

Fundamentals & Fundamentals & ApplicationsApplications

Agricultural Agricultural MechanicsMechanics

Fundamentals & Fundamentals & ApplicationsApplications

UNIT 19—Figuring a Bill UNIT 19—Figuring a Bill of Materials (BOM)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)

144Or: 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 lb = pound‘ or ft = foot d = penny(nails)yd = yard NC= Nat’l coarsemi = mile NF=Nat’l fineea = each NPT=Nat’l pipe@ = atN/A = not applicablept = pint

Standard AbbreviationsLF = linear footBF = board footS1S = surface 1 sideS2S = surface 2 sidesS3S = surface 3 sidesS4S = surface 4 sidesNo. /# = numberin² = square inchft² = square footyd² = square yard

Standard AbbreviationsSquare = 10’ X 10’ or 100 square feetNC = national coarse threadsNF = national fine threadsNPT = national pipe threadsd = penny (nails)lb = poundsCwt = hundredweight (100 lbs)

Lumber• Available in 6’, 8’, 10’, 12’, 14’, 16’,

– Special orders for 18’ & 20’

– Widths• 1x6 2x4• 1x8 2x6• 1x10 2x8• 1x12 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.