1.Stainless spring washer 2.M2,M3,M4,M5,M6-M30,1/8",3/16...1 1/8" 3.304 ,316 (stainless A2,A4), 4. ... standard:GB,DIN,ASME,ANSI Stainless spring ... washer- 304,316 ,and we also provide as below: Features (material: 304, 304L, 316, 316L, etc.):1) M5 ... DIN934 and ANSI/ASME Hex Nuts2) 1/4"~5/8" ANSI/ASME B18.2.1 Hex Head Screws 3) M6~M20 ...