UNE 36-034-85 specifies non-alloy and alloy steels, with or without boron, supplied in coils or bars for manufacturing bolts, screws, studs, and other high-strength fasteners by cold heading, cold extrusion, or upsetting. The standard covers steels used in the quenched and tempered condition.
It defines steel designations, chemical composition limits, hardenability, tensile properties, grain size, spheroidization of cementite, upsetting suitability, surface quality, decarburization limits, manufacturing and supply conditions, inspection units, sampling, testing procedures, dimensions, and tolerances. The standard includes steel grades such as C35 DF, 35 Mn5 DF, 38 Cr4 DF, 41 Cr4 DF, 35 CrMo4 DF, 40 NiCrMo2 DF, and boron-containing grades.
Application Scope: Applicable to producers, purchasers, quality-control laboratories, and fastener manufacturers working with cold-forming steels for high-strength bolts, screws, studs, and related fastening components.
