Process Overview

Metalink's Manufacturing Process:

  • As illustrated in Fig. 5, there is shown a schematic view of a bi-metal screw which is made of stainless steel AISI 304/316 head 5 and threaded bolt 6, as well as a drilling portion including self-tapping section 7 and a drilling end section 8 which are formed of carburized steel materials.

    The heading process of stainless steel part is shown as Fig. 1, an Austenitic stainless steel round rod is composed of a pre-formed head 51 and a non-threaded bolt 61.

  • The heading process of low carbon steel part is shown as Fig. 2, a pre-formed shoulder 9 formed from low carbon steel. A round rod is provided including  non-threaded bolt 71 and a shaped drilling end portion 81. The carburized area is shown as the coarse black line C.

  • The welding process is shown as Fig. 3, The round rod side 61 is welded stainless steel head together and the partially product is finished.

  • The deburring process is shown as Fig. 4, The weld flash 62 and the shoulder 9 is cut or removed. It has a L width non-carburized area and near the welded interface W.

  • The threading process is shown as Fig. 5, The whole thread of screw is formed.

  • The induction heating process is for the quenching & tempering of the carburized part and adjust it's hardness to be good for drilling.

  • The Zinc plating or Ruspert coating process is for increasing the lubrication and anticorrosive function of screws.

  • The packing process would be performed for shipment.