3.175mm Stainless steel ball aisi 420 440 1)100% original 2)High hardness 3)good resistance ... : SAIGEMaterial: Stainless SteelProduct Name: stainless steel ballMaterial: AISI304,316,316L,420,440,200,202MDiameter: 3.175mmGrade: G10-G1000Certificate: ISO9001:2008 SGS ... Development, Service for reputation. 3.175mm Stainless steel ball aisi 420 440