The most acceptable metals for conductors are copper and aluminium due to their higher conductivity and ductility. The most economical construction for conductor is solid conductor i.e. conductor is made of one single wire. As the area of conductor increase, solid conductor becomes more stiff and rigid hence difficult to handle.

In this case stranded construction is gradually adopted. Here the conductor is made of number of strands. The strands are arranged in spiral layers in 1+6+12+18+…….. formations. I.S. 1554 & I.S. 7098 permits solid conductor construction upto 10 in Aluminium and upto 6 in copper. It permits the use of shaped conductors for sizes from 16 onwards.