As a rule of thumb, sintered carbide rolls are recommended for annual productions of over 1 million meters of tubes of hard material. The life can be 5-10 times that of tool steel.
Some lubricant (oil or soap water) can be used to reduce bending of the element. Worn rolls increase bending.
As a rule of thumb, the minimum safety distance bewteen tubes should be 500 mm, or one third of the element length, in order to make place for elongation. If this is not respected, a failure may occur which may result in bent shafts, cracked bearings or cracked rolls
(sintered carbide rolls).