| 摘要 |
<P>PROBLEM TO BE SOLVED: To make corrosion resistance of a fracture surface of a torque-limiting fastening device stronger than that of a surface without coating of an inner base material. <P>SOLUTION: The torque-limiting fastening device has a first head part 11 including at least one shape element having a shape allowing attachment of a fastening tool, and a second head part 12 including at least one screw thread. These two head parts are mutually connected via a fracture part 4 fractured so as to generate a first fracture surface in the first head part 11 and a second fracture surface in the second head part 12 when a torque exceeding a border value is given between both head parts. At least the second head part of these two head parts includes the inner base material and a corrosion-resistant surface layer. The corrosion resistance of the second fracture surface formed in the second head part 12 is made stronger than that of the surface without coating, of the inner base material of the second head part 12. <P>COPYRIGHT: (C)2012,JPO&INPIT |
