3. Optimization of the structure of hearth rolls: Link above
（1）. Diameter of outstretched shaft affect the mechanical properties of the hearth rolls. In Figure 3 shows the results below we can see, with the increase of the diameter, the value of the torsion deformation resultant vector decreases.
From 0.664E-3 down Low to 0.512E-3, to improve the Stiffness of hearth rolls. But when diameter of elongate shaft increases from 40mm to 60mm, the maximum stress values did not change significantly, diameter of outstretched shaft d generally selected about 60mm when designing.
(2) Effect of thickness of ring plate to mechanical properties of hearth roll. In Figure 4 below shows he results. When changes in the thickness of the ring plate of hearth roll (t = 50mmt = 100mm), Impact strength and stiffness of the hearth roll more obvious.
When the thickness of the ring plate is reduced, the strength and rigidity of it is weakened. Thereby increasing the possibility of damage of the hearth rolls under billet weight motor drive and furnace temperature interaction.