钻孔扩孔
bore hole drilling and enlarging
250B轴承环扩孔机
250B bearing ring rolling machine
冲孔与扩孔
punching and hole-expanding
大直径挖孔扩底灌注桩
large-diameter cast-in-situ piles with enlarged ba
带扩孔端的抗拔桩
uplift pile with hole expansion end
定向钻扩孔
reaming operation in directional drilling
多节扩孔桩
multi-under-reamed bored piles
多孔扩散型消声器
Porous diffusion type silencer