| 摘要 |
A male conical thread of an elongated steel structure, e.g. a steel rod or wire of the type employed as reinforcement in pre-stressed concrete, for use in engagement with a matching female conical thread provided in a fixing sleeve or other nut means is formed by first shaping an end portion of the wire or rod, e.g. by grinding or hammering, into a cone that tapers down towards the end of the rod or wire and has a generally truncated smooth outer surface; then, the cone's surface is deformed by cold-pressing such that the thread is formed. Further, a press-die appartus is disclosed for use in such cold-pressing, e.g. at a construction site where steel reinforcements are mounted. |
