Stainless steel hexagon screw material generally has stainless steel SUS201, stainless steel SUS304, stainless steel SUS316 of these.Customer common stainless steel hexagonal corner screw with the brain with knurled and without knurled two.Distinguish what is stainless steel hexagon material, a few kinds of way.The first kind is eye of choose and employ persons, this must have more rich and colorful screw professional technical personnel or clerk.But choose and employ persons see stainless steel hexagon screw is what material to pledge after all, can have deviation commonly, besides this not quite accurate.The second method is to take the medicine water to test.Detect the liquid point of stainless steel which material is a few in stainless steel hexagon screw, if the color will fade, will become bright red, that is to say stainless steel SUS201 hexagon screw, if not fade that is to say stainless steel SUS304 or so level of screw.Generally in the stainless steel hexagon screw head with straight knurling processing process can be distinguished for the pure SUS304 production of screws.Stainless steel hexagon socket screws without knurling on the head are considered to be of a slightly inferior material or low nickel content.