During which phase of mitosis do the spindle fibers to pull the chromosomes to the center of the cell, where they line up?

Metaphase - Parallel fibers appear once the metaphase starts, and these are known as spindle fibers. The fibers attach to the centromeres of each chromosome. The spindle fibers make the chromosomes form into a tight kind of circle that surrounds the circumference of the spindle apparatus. There is an invisible line at which the chromosomes are aligned, that is called the metaphase plate