PURPOSE: To enable the production of a thick walled hollow bar material having excellent out of roundness without using any tool such as plug or mandrel by drilling the round bar steel material along the central axis thereof, and drawing and rolling the same with a skew rolling mill having 3W4 pieces of cone type rolls.

CONSTITUTION: A round bar steel material A1 is drilled along the central axial line thereof by machining with a drill 1 to form a hollow blank material A2, and after the material is heated in a heating furnace 2, it is drawn and rolled with a skew rolling mill 4. Or the material A1 is heated in the furnace 2, is pierced with a hole in the central part with an extruding machine 3 and is drawn and rolled with the skew rolling mill, whereby the thick-walled hollow bar material A3 having an intended outside diameter and ≥(25W30%) wall thickness/outside diameter ratio is produced. If the crossing angle and inclining one of the cone type rolls of the skew rolling mill are controlled in this case, the thick-walled hollow bar material having excellent out of roundness is produced with good dimensional accuracy.