... Automotive, medical device, electronics,toy and so onThis spring will not be magenetic field,not fever,not be broken ... be used in various corrosive mediumsMain material: carbon spring steel, alloy spring steel, refractory steel, stainless steel, high temperature ... is okStandardGB,GB/T,DIN,JIS,BSW,ANSI,ISO & non-standard productsSurfacePlain, Yellow zinc, black phosphated, grey phosphated, ...