Years ago, I had an experience that made me care more about the milling tolerances for products I install. The floor was a 5″ hickory floor that the homeowner purchased online from some mill in another state. I rarely am asked by a customer or general contractor to install hardwood material that my company does not provide. In this case, I agreed to install the material and made a mistake of assuming the quality was good. This turned out to be a major mistake because on average one out of every three boards was milled 1/16-1/8″ to wide or too narrow. This may seem trivial until you consider that forcing this material to become straight was virtually impossible. The floor may appear to be straight and well sealed early on, but after a few seasons of an improper fit the boards will win out over the fasteners and cause a loose floor. To the bargain hunters of flooring material, there is often a reason the price is too good to be true. A low price is a likely indicator of mis-milled product that was sold to reduce inventory for a mill, distributor, or retailer.