Percussive drilling with independent rotation

Author:	Unger, Harold F.
Additional Authors:	Fumanti, Robert R.
Year:	1972
Document Type:	BMRA
Issuing Agency:	U.S. Dept. of Interior, Bureau of Mines,
SUDOC:	I 28.23:7692
Series:	Report of investigations / United States Department of the Interior, Bureau of Mines ;
Report Number:	7692
Subjects:	Drilling and boring machinery
	Boring
	Percussion drilling
Link:	https://hdl.handle.net/2027/mdp.39015078478149