Spike forming method

摘要

The present invention relates to a method for forming a blank railroad spike using a series of cold forming dies. A workpiece is introduced into a first die to form a first stage spike having a squared end and a thick cylindrical shank. The first stage spike is introduced into a second cold forming die to form a second stage spike in which a lower portion of the shank is decreased in diameter, while a upper portion of the shank maintains the same diameter as in the first stage spike. The second stage spike is introduced into a third cold forming die to form a third stage spike in which the upper portion of the shank is compressed to form a collar for the spike. The blank spike is subsequently introduced into a thread cutting apparatus to form the finished threaded spike.