1,material steel 2,certificate: ISO9001-2008 3,Grade:4.8 5.6 8.8 10.9 12.9. 4,Surface: plain, Zinc,HDG Dacromet Product Name:Track bolt Fish bolt1. Surface treatment: Nuture, black, pot galvanizing, cold galvanizing, oil, parkerising etc.2. Grade: 4.6, 5.6, 8.8, 10.6 and12.93. Dia: from M16 to M404. Length: unrestricted5. Standards for railway products: T B, UIC , AREA, etc. standard components: ...