E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B10/00—Drill bits
E21B10/36—Percussion drill bits
E21B10/40—Percussion drill bits with leading portion
E—FIXED CONSTRUCTIONS
E21—EARTH OR ROCK DRILLING; MINING
E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B10/00—Drill bits
E21B10/44—Bits with helical conveying portion, e.g. screw type bits; Augers with leading portion or with detachable parts
E21B10/445—Bits with helical conveying portion, e.g. screw type bits; Augers with leading portion or with detachable parts percussion type, e.g. for masonry
E—FIXED CONSTRUCTIONS
E21—EARTH OR ROCK DRILLING; MINING
E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B10/00—Drill bits
E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
E21B10/54—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of the rotary drag type, e.g. fork-type bits