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'' 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 coarse mi = mile NF=Nat’l fine ea = each NPT=Nat’l pipe @ = at N/A = not applicable pt = pint

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 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.