DIFF Subgroup
E21B 1/38 Hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member
Introduced: January 2000
Full Title
Percussion drilling > Hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member
No child classifications to compare. This is a leaf node in both IPC and CPC.