This standard concerns the dimensional tolerances, the mechanical characteristics and the conditions of the possible zinc coating of the drawn non-alloy steel round wires2' intended for the construction of ropes for general applications, including ropes for cranes, excavators and naval uses. 2 It does not apply to wire ropes having special applications, namely:
——mining ropes;
——ropes for deep drilling;
——ropes for aeronautical applications;
——lift ropes;
——ropes for aerial and land funiculars;
——reinforcement ropes for pre-stressed concrete;
——ropes for reinforcing tyres, belts, pipes, conveyor belts and other elastomeric articles. 3 This standard considers:
——bright wires with nominal unit tensile breaking load (strength class) (see point 3.1.) of 180 kgf/mm2 (1 770 N/mm2) with diameters from 0.20 to 3.70 mm excluded;
——galvanized wires of three different galvanizing classes with nominal unit tensile breaking loads (strength classes) (see point 3.1.) and nominal diameters according to the following table. Galvanizing class Unit breaking load a (class of kgf/mm2 or nominal tensile strength) N/mm2 Nominal diameter d mm A 145 1 420 from 1.00 to 3.70 excluding 160 1 570 AB 145 1 420 from 0.40 a 1.90 excluding 160 1 570 180 1 770 B 160 1 570 from 0.20 to 3.70 excluding 180 1 770
UNI 7304-1974 history
1974UNI 7304-1974 Non-alloy steel finished products. Silk material. Steel wire for general purpose ropes, partially replacing UNI 1477-UNI 1488