SBAC TS 121 Issue 4 (2004) Manufacturing Specification For Studs, Bolts And Screws In Dtd 5639, En 2959 And En 3220 Material 1210 Mpa (175,000 Lbf/in[2]) Tensile At Room Temperature (for Which Forging Is Optional And Qualification Not A Requirement) Gives the requirements for studs, bolts and screws in DTD 5639, EN 2959 and EN 3220 material (for which forging is optional and qualification not a requirement).