... ''~1 1/4''(M16-M30)5.Surface treatment: Hot dip galvanized6.packing: export carton and wooden pallet or wooden ... of headSquare, or according to custmoers' requirementsSurface treatmentBlack, Hot-dip galvanization, Electro-galvanization, Dacroment and so on.Dia. Over ... 1 1/4'' 5.High tensile Description(TC bolt) Torshear type high strength bolts for steel structureMaterialAlloy steel ,carbon steel, ...