A core bit having a spiral shank shaped drill shank, and a method for manufacturing a spiral shank shaped drill shank to a core bit

摘要

The present invention relates to a core core (10) for manufacturing a drill core (24) having a core diameter (d ₁ ) and a drill hole (25) having a drill hole diameter (d ₂ ) in a workpiece (23). A drill shank portion 11 having a drill shank 18 shaped; A receptacle portion 12 having a cover 19 and an insertion end 20; And a connecting device 13 connecting the drill shank portion 11 and the receptacle portion 12 to each other releasably or non-releasably, wherein the tubular drill shank 18 is a welded spiral tube. It is formed as.