Nonstock Item Quantities in a BOM

I am trying to reference non-stock items on a Bill of Material that we want to display on a manufacturing work order. Whenever I add the quantity to the BOM and save the BOM, it makes the quantity and unit of measure blank. We want to reference a quantity of "general steel stock" that is non-inventory, but is required to make the part. The quantity is important so they can look at the steel rack and see if we have enough to make the order.