硬质合金焊接式锥柄扩孔钻
carbide welded taper shank core drill
直锥柄扩孔钻
straight taper shank core drill
锥柄三刃扩孔钻
taper shank three-edge hole-dilating drill
直柄扩孔钻
Core drills with parallel shanks
parallel shank core drill
钻孔扩孔
bore hole drilling and enlarging
扩孔钻和锥管丝锥复合刀具
combined taper pipe tap and core drill
两级锥柄钻头
two-step taper shank drill
定向钻扩孔
reaming operation in directional drilling