At present, the related technical specifications of copper clad steel wire are based on the American Standard. The the related technical specifications of copper clad steel wire are now dominated by the American Standard, generally, ASTMB227, ASTMB228, ASTMB229 and ASTMB910 are cited, and its features include: electrical conductivity (resistivity, resistance or copper layer thickness), tensile strength, cross-sectional area (number of strands as well as the diameter of a single line), strand distance, modulus of elasticity, elongation, condition (H for hard state, HS for super hard state, A for annealed soft state), packaging requirements, etc.

The end diameter is√ strands * 1.15 * single diameter (single line < 0.3mm) and √ strands * 1.25 * single diameter (single line > 0.3mm), the total cross-sectional area can be budgeted for a single cross-sectional area * number of strands, the reality is slightly larger than the calculated cross-sectional area. The 3 stranded wires are crossed type, in pitch turned over, the three diagonally placed single line can be seen.

More than strands of stranded wire is vertical for the middle strand, but also the cross-type for its surrounding, open in pitch, the oblique placement of a single line can be seen, the principle of reference is the basic principle mentioned in the three-dimensional geometry of secondary school, of which ants climbing the surface of a cylinder. Just because most of the stranded single line is oblique, when the 1 km length of stranded line is turned over, the actual single line length is uniformly greater than 1 km, which involves accounting coefficients, with reference to the U.S. specifications.

XX stranded wire increase factor of 0.8%; 7 stranded wire increase factor of 1%; 19 stranded wire increase factor of 1.4%, 37 stranded wire increase factor of 2%, coefficients can be used directly to account for the entire stranded wire kilometer resistance and kilometer component. (Assuming the need for more accurate accounting, see the U.S. specification Part 10 and NBS Manual 100) In terms of the breaking tension of copper clad steel wire, 7 strands of stranded wire is a single wire breaking tension of 90% of the cumulative, 3 strands of stranded wire is a single wire breaking tension of 95% of the cumulative, for the degree of accounting, see single wire density algorithm?