4/4" #2 common Sap & Better Hardwood Lumber
15000 FBM* of Random Widths and Random Lengths available at $1.60/FBM
Hard maple is, as the name suggest, a dense wood with good hardness, making it one of the best species for making hardwood flooring.
*Note that 1 FBM (board foot) is a volume of wood measuring 12" long x 1' wide x 1" thick.