Process for producing blanks of rings

A process for producing rolling-bearing ring blanks made of bearing steel,

• the process comprising the steps of:
• i) providing a hot-rolled tube made of bearing steel and of irregular inner and outer diameters, irregular wall thickness, or irregular concentricity between said diameters;
• ii) dividing the hot-rolled tube into a plurality of bearing steel slugs each having an axial through hole, each bearing steel slug retaining at least one of the irregular inner and outer diameters, irregular wall thickness, and irregular concentricity of the hot-rolled tube;
• iii) supplying the bearing steel slugs to a die assembly of a cold-forming station without any preliminary machining operations, the cold-forming station also including a punch assembly;
• iv) subjecting the bearing steel slugs to contained forward extrusion through the die assembly, wherein a thrust imparted by a pushing member of the punch assembly on a subsequent bearing steel slug causes passage of a preceding bearing steel slug through an axial through cavity of the die assembly and cold deformation thereof into a rolling-bearing ring blank, while a restraining member of the punch assembly occupies the axial through hole of the subsequent bearing steel slug and at least part of the axial through hole of the preceding bearing steel slug.