| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high-hardness aluminum tapping screw which promotes recycling of an aluminum product and allows mass production of the high-hardness aluminum tapping screw, and a method of manufacturing the same. <P>SOLUTION: In a tapping screw 1 formed by performing a surface treatment to a screw material comprising a head part 2 and a leg part 3 having a thread 10, since this high-hardness aluminum tapping screw includes a coating film of a laminated structure to which an electrodeless nickel plating treatment followed by a zinc plating treatment is performed after the screw material is made of an aluminum alloy, the thread 10 is formed on the leg part 3 of the screw material by form rolling, and a solution heat treatment is performed to the screw material formed with the thread 10, the tapping screw can be screwed in a prepared hole of a workpiece made of an aluminum alloy while directly forming a female screw by a screw component of the same material. A plated coating film is smoothly formed, the cause of occurrence of corrosion is eliminated and corrosion resistance is improved. Since both the workpiece and the screw are formed of the aluminum alloy, the need of sorting treatment is obviated and the rate of recycling is improved. <P>COPYRIGHT: (C)2012,JPO&INPIT |
