Method for cold forging high strength fastener from austenitic 300 series material

摘要

The present invention pertains to a method (3) for cold forging high strength fastener with austenite 300 series material comprising the procedures of initially preparing a raw austenite shaft (41) and then proceeding through a cold forging method to reduce its diameter (d1) for thereafter generating a preliminary shank (42), which can undertake above 1/2 force more than the raw shaft; further passing through the following formations of the head (43), the drill portion (44) and threads (45) in sequence to build an integral fastener (4). Thus, the entire cold forging facilitates to fabricate the fastener with high strength and hardness by lower manufacturing cost and with effective corrosion resistance, so as to firmly drill the fastener into objects and increase the screwing security.