PLUG USED IN PIERCING MACHINE AND PLUG REGENERATION METHOD

摘要

It is an objective to provide a plug capable of enhancing a usage count of the plug, which is for use in a piercing machine for piercing-rolling a billet, and a regenerating method of the plug. The plug (10) is for use in a piercing machine (30) for piercing-rolling a billet (36). The plug (10) includes a body (18), a columnar portion (20), and a sprayed film (16). The body (18) has a maximum diameter at its rear end. The columnar portion (20) has the same diameter as the diameter of the rear end of the body (18), and extends from the rear end of the body (18). The sprayed film (16) is formed on a surface of the body (18) and on a surface of the columnar portion (20).