R22 R25 R28 R32 R38 extension rod drill rods are made by hollow
drill steels; there are two shapes of extension rods, round type
and hexagonal type. This hollow hole are usually named flushing
hole, used for transmitting water or air during drilling. And the
threads can be used for connecting couplings, shanks, couplings or
bits.
Usually for 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: T38 T45 T51 Male-Male Rod, MF Rod
(2) Thread: R22, R25, R28, R32, R38, T38, T45, T51,
(3) Rod size: hex. 22mm, hex. 25mm, hex. 28mm, hex. 32mm, hex.
35mm, dia. 39mm, dia. 46mm. dia. 52mm
(3)Length: 0.4m-6m
(4)Package: in wooden case or in bundles.
(5)Productivity: 20000MT/month
