Hex Washer Head SDS With Ribs (DIN7504K) Hangzhou Huachao Fastener Co., Ltd. Base Info Model NO.:2011092208Trademark:Hangchao or OEM serviceOrigin:Hangzhou, China(Mainland)HS Code:73181400 Description Pre:Square Csk Head Self Tapping Screw (C1022) Next:Hex Washer/Flange Self Drilling Screw (DIN7504K)