| 摘要 |
PURPOSE:To obtain a nipple having a high strength at a low cost by cutting a steel-wire material containing C: 0.05-0.6% and S<0.045 to a certain length and forging said steel-wire material to form a nipple. CONSTITUTION:A steel wire material B contains C: 0.05-0.6% and S<0.045, and has a penetration hole (b) and is set to a certain length. Said steel wire material is heading-worked from one side and a head part 21 and a trunk part 22 are formed. In the next work, the squeezing work for a clearance hole 25 is carried- out and the hole (b) is squeezed and a preparatory hole 27 is worked, and then the material is applied with chamferring and tapping to form a nipple M. |
