PURPOSE: To provide a roll capable of avoiding cracking at subjecting to repeating impact at passing of welded part of steel strip in a forming roll equipped in an electric welding tube machine.

CONSTITUTION: The forming roll, which has ≥0.015kgfm/cm2 Charpy impact value and has a composition consisting of a principle component of any one kind among silicon nitride, zirconium oxide, sialon and the balance 25wt.% sintering assisting agent, is produced. The roll is incorporated in an electric welding tube making machine, it has excellent power saving effect and electric corrosion inhibition effect of bearing, further it is free from damage at subjecting to repeating mechanical impact, the roll life is greatly prolonged.