Square neck bolts (1) round head square neck bolts: GB14 / DIN603 (2) less than half head square neck bolts: GB12 (3) low semi-circular head square neck bolts: GB801 Notes: square neck bolts carriage bolts and hex-head screws (1 ) hexagon socket head screws: GB70 / DIN912 (2) Hexagon socket set screws: BG70 / DIN913 (3) Hexagon tip set screws: within GB78 / DIN914 (4) countersunk head Socket Head tail set screws: GB79 / DIN915 (5) Hexagon socket set screws: Hexagon thin head screws DIN7991 (7) inside:: GB80 / DIN916 (6) hex head screws DIN7984 (8) a Cypriot screws: ISO7379 produce stainless steel screw locking phenomenon The external reasons :) urging angle in the wrong direction. In use, the nut must be perpendicular to the axis of stainless steel screws screwed one but it is easy to tilt lock. People often think that magnets magnetic stainless steel, 304 stainless steel screws Qihe verify the authenticity of their advantages and disadvantages, and 304 stainless steel screws, do not attract non-magnetic, considered a good, plain 304 stainless steel screws, genuine; sucked by magnetic, then believed to be counterfeit fakes. In fact, this is an extremely one-sided, no practical method to identify errors. Many types of stainless steel screws, according to the organizational structure at room temperature can be divided into several categories: 1. Austenitic: If 304,321,316,310, etc; 2. Martensite or ferrite: as 430,420,410 and the like; austenitic type is non-magnetic or weakly magnetic, martensite or ferrite is magnetic stainless steel screws Jinan 304 | 304 stainless steel screws | Jinan Road ground By Jinan Daoqin Trading Company. Jinan Daoqin Trading Company (www.daoqinshangmao.com) (www.daoqinshangmao.com) to provide "304 series stainless steel screws, nuts, washers, retaining rings, cotter pins, micro" business, the company has "Daoqin Dongming "brands. Focusing on hardware accessories and other industries, in Jinan, Shandong have high visibility. Welcomes inquiries, contact: Chuan-use.