... : 302, 304, 316, 130M, 304ES, 201CU, 631, 200CU, 200CU- Stainless steel spring wire products: A) Material Classification: 200 series: 201, 202 ... : Magnetic / Nonmagnetic F) Shape classification: Round wire; Half Round Wire; Square wire; Pressure flat wire; Precision shaped wire bright Stainless Steel Spring Wire