AASHTO M 160M/M 160-08, Standard Specification for General Requirements for Steel Plates, Shapes, Sheet Piling, and Bars for Structural Use, collects the requirements that apply across AASHTO structural steel specifications rather than to a single product. It addresses manufacturing and chemical composition, tensile and bend requirements, permissible variations in dimensions and mass, workmanship, marking and shipping. Because these general provisions are invoked by the individual material specifications, the document is used by producers, fabricators, testing laboratories and inspectors to check that steel supplied for highway structures meets a common baseline.