DIFF Subgroup
E21B 19/18 Connecting or disconnecting drill bit and drilling pipe
Introduced: January 1980
Full Title
Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables > Connecting or disconnecting drill bit and drilling pipe
No child classifications to compare. This is a leaf node in both IPC and CPC.