Patents Assigned to Chieh-Chang Tzeng
  • Patent number: 5205466
    Abstract: This invention is a manufacturing method of Austenitic stainless steel self-tapping and self-drilling screw. It uses low carbon steel or low carbon alloy steel and forges or cuts it into a round rod with a shoulder, non-threaded bolt, and drilling end portion. After it is carburized and properly heat-treated, it will be welded together with an Austenitic stainless steel round rod which has a non-threaded bolt. And then the welded flush and shoulder will be cut so that a non-carburized hardened area in a proper width can be formed. Lastly it is threaded and quenched so as to manufacture a screw whose head and threaded stem joint are high corrosion-resistance and whose carburized drilling end portion has a high self-tapping and self-drilling function.
    Type: Grant
    Filed: July 15, 1992
    Date of Patent: April 27, 1993
    Assignee: Chieh-Chang Tzeng
    Inventor: Yao-Tin Ker