Abstract: The main characteristics, intermediate tests and trail production of the three roll 108mm diameter tube piercer as well as its improvement are described. Production experiences gained from putting into production of the piercer matched with a three roll mill are summed up. Steel grades capable for piercing, shell sizes, inside and outside surface quality, wall thickness accuracy and conditions of plug state in use are also described. The piercer which has the primary function of piercing and reduction is siutable for piercing low plastic shells and continuous cast billets. With the ratio D/S within the optimal range of 6.85, high quality shells can be obtained by high speed piercing. The piercer is better to be matched with the elongator which has a large amount of deformation or the one which produces the tubes with medium wall thickness.