Acicular sphero rolls are produced from high alloy spheroidal graphite cast iron material. 

After casting, these rolls are treated through a long-time, low-temperature annealing process which is primarily applied for the purpose of relieving the internal stresses, as well as to ensure the complete transformation of possibly retained austenitic phase in the microstructure.

This microstructure named as acicular structure is obtained through formation of bainitic and needle structured martensitic carbides. 

The demand for special quality of rolls with resistance to thermal shocks and wear, required for slitting systems which have now wider use in rolling mills are met with SD-BM-73S quality.

  • Cr, Ni, Mo alloyed spheroidal cast iron
  • Bainite + Martensite + Carbide + Spherolite
  • Hardness drop
  • Tensile strangth: 500 – 700 N/mm2, Bending strength: 800 – 1000 N/mm2
  • On intermediate stands for slitting
  • Resistance to wear
  • Sensitive to firecracks, attention to cooling

hardness profile


chemical analysis & hardness

C% Si% Mn% Cr% Ni% Mo%
68-73 3.2 - 3.7 1.0 - 1.6 0.3 - 0.8 0.3 - 0.8 3.5 - 4.5 0.5 - 1.0

© Silvan Sanayi A.Ş.