Making steel balls for large bearings - GIF

[Frank S]

I make these balls between 150 - 200 mm. If they were destined for crushing cement, would they not be made of cast iron?

When we used to work the shut downs at the TXI plant in Midolothian TX They would sometimes change out the balls in the mill and run them through a qualifier any balls less than 40 mm or just a little over 1 1/2 inches went to the scrap pile 40 to 80 mm were saved to be placed in a different mill above 80 mm were returned to the mill new balls for their largest mill were 100 mm
They could be torch cut in half so I doubt if were cast iron
Cast iron could be poured and made into round bar stock and passed through a die much the same as what was shown in the video