Hex. Head Bolt & Nut M16 X 65 Mm, Product Grade - 'C', M.S. Black. Matl.& Specn : Is: 13 63 (Part - 1) / 2023 (6Th Rev.) And Is: 1363 (Part - 3) / 2018 (5Th. Rev.) , Property Class 4.6 For Bolt And Property Class 5 For Nut. [ Warranty Period: 30 Months After The Date Of Delivery ] ]