I have added information on my web page www.mykaltx.com to help.
I got some great input from some of the other users.
I appreciate all the help.

The spreadsheet is now able to calculate the weight of steel beams, pipe, angle channel and plate.
What I need now is for it to calculate the weight of a trapezoid. The spreadsheet will have to use the weight for plate. The kicker is it will have to calculate the weight for plate the top width the bottom width and the length as well.
If you have any ideas let me know.

Also I am not that great at explaining myself. Let me know if I need to clarify.

I have added my formula for trapezoid weights. I have also added a page that show a new formula.

Here is the formula I am having problems with.
=IF(ISERROR(VLOOKUP(G21,Sheet2!A:B,2,FALSE)),"", IF(LEFT(G21,2)="PL",((O21*12+Q21)*(W21*12+Y21))*VLOOKUP(G21,Sheet2!A:B,2,FALSE)/144*D21,((W21*12)+Y21)*(VLOOKUP(G21,Sheet2!A:B,2,FALSE)/12)*D21))