Hex. Head Bolt & Nut, M20 X 65 Mm, Product Grade 'C', M.S.Black.Matl.& Specn : Is: 136 3 (Part - 1) 023 (6Th Rev.) And Is: 1363 (Part - 3)/2018 (5Th. Rev.), Property Class 4.6 For Bolt And Prop Erty Class 5 For Nut. [ Warranty Period: 30 Months After The Date Of Delivery ] ]