To elongate the life of the tie bolt of the main clutch drum in a cold Pilger mill by easily carrying out the reuse of the tie bolt even if the tie bolt has been broken.

In the tie rod for fixing the main clutch drum to the brake drum in the cold Pilger mill, a thin type hard lock nut 13 is used for fixing the long tie bolt 9a to the brake drum 1, and a combined belleville spring 15 is inserted between the thin type hard lock nut 13 and the brake drum 1. The impact force applied on the long tie bolt 9a is relaxed by the combined belleville spring 15. Further, the breakage of the long tie bolt 9a is prevented by fitting a long collar 14 thereon. If the long tie bolt 9a has broken, the long collar 14 is exchanged for a short collar 14a, and the thin type hard lock nut 13 is newly fastened on the rest portion 9c of the broken long tie bolt 9a to restore the breakage of the long tie bolt 9a.