Extension rods, there are R22, R25, R28, R32, R38, T38, T45, T51, ST58, T60 threads, and different lengths of rods are available from 600mm to 6400mm usually. ( 1) Steel grade: 20CrNi3Mo equivalent to SANDBAR 64 SIZE: hex.22mm .hex.25mm, hex.28mm. hex.32mm hex.35mm Dia.32mm. dia.38mm, dia.45mm dia.51 mm ( 2) Thread: R22, R25, R28, R32, R38, T38, T45, T51, ST58, T60 ( 3) Length: 0.4m-10m ( 4) Package: in wooden case or in bundles. ( 5) Productivity: 20000MT / month