ballast rod

基本解释冲唤钻杆

网络释义

1)ballast rod,冲唤钻杆2)chisel bit,冲唤钻头3)churn drilling,冲唤钻进4)percussive machine drilling,冲唤钻眼5)thrust borer,冲唤钻机6)boring with line,钢绳冲唤钻进