HIGH-TEMPERATURE SELF-SCREWING SCREW PART AND MANUFACTURE THEREOF

摘要

PURPOSE: To keep the self-fastening capability at high temperature by providing a patch of fused high-temperature resistant resin powder which is adhered to at least a part of the screw part of a fastener and exposed to a specified temperature and satisfies a specified lowest removing torque request. CONSTITUTION: In order to impact a fastener patch 3 consisting of high- temperature resistant resin to a screw part 1, fine powder of a high-temperature resin particle is exposed to a temperature of 400 deg.F for 3 hours or more many times and sprayed to one side or both sides of the heated screw part 1 or the whole circumference thereof. The resin material contains semi-crystal polyphthalamide generated from a monomer such as hexamethyl isophthalamide or heptamethyl isophthalamide and a mixture thereof. The screw part is removed at 450 deg.F, so that the removing torque is conformed to MKL-F-18240E standard to the entire removal at high temperature or exceeds it. According to this, the screw part resistant to high temperature capable of keeping the self-fastening capacity can be maintained.