... drill rods and integral drill rods, MF drill pipe.extension drill rod.mainly used for mining, coal cutting, tunneling, rock cutting ... in quarrying.T38 extension drill rod,length from 1220mm,1525mm,1830mm,3660mm to 6095mm.T45 ... extension drill rod,length from 1220mm,1525mm,1830mm,3660mm to 6095mm.T51 extension drill rod,length from 1220mm, ...