Manufacturing method of austenitic stainless steel self-tapping and self-drilling screw
AssigneeChieh-Chang Tzeng
InventorYao-Tin Ker
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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.
Claims4
A method of manufacturing an austenitic stainless steel self-tapping and self-drilling screw formed from low carbon or low carbon alloy steel including the steps of:
- (a) forming a low carbon or low carbon alloy steel rod having a rod shoulder section, a rod non-threaded bolt section and a rod drilling end section;
- (b) carburizing and heat treating said rod to a predetermined carburization depth to provide a carburized portion of said rod;
- (c) establishing an austenitic stainless steel rod having a head section and a non-threaded bolt section;
- (d) welding said austenitic stainless steel non-threaded bolt section to said rod shoulder section in aligned relation thereto forming a weld flash;
- (e) removing said rod shoulder section and said weld flash to provide a non-carburized section of said rod;
- (f) threading said rod non-threaded bolt section and said austenitic stainless steel rod non-threaded bolt section.
Dependencies are inferred from the claim text.