Stainless Steel Wire Spring Wire Steel grade: 302, 304, 316, 130M, 304ES, 201CU, 631, 200CU, 200CU- Stainless steel spring wire products: A) Material Classification: 200 series: 201, 202 300 series: 301, 302, 304, 304L, 304H, 309S, 310S, 316, 316L, 321, 347 400 series: 410, 420, 430, 431, 434 B) Hardness Classification: Soft | 1/4H | 1/2H | 3/4H | H | EH |SH C) Surface Classification: Bright; ...