Extension rods R32-HEX 28-R28, 2700mm
Extension rods are one major spare part in terms of drill
application area, there are two shapes of extension rods, one is
round type, another one is hexagonal type. But all extension rods
are threaded and made by hollow drill steels, this means usually
extension rods are hollow. This hollow hole are usually named
flushing hole, used for transmitting water or air during drilling.
Two ends threads can be used for connecting couplings, shanks,
couplings or bits. Typically two ends of extension rods are male,
while sometime one end is male and another one is female, then we
call it M/F rod. We need couplings to connect extension rods, while
for MF rods, male and femal rods, because one end is female, so
couplings are not necessary.