extension rod/drifter rod 1.T38,T45,T51 2.manufacture of series drill rod 3.professional technical team 4.ISO9001:2008 drifter rod ... /extension rod/speed rod for drfting and tunneling :Our ... for mining, coal cutting, tunneling, rock cutting in quarrying.T38 extension drill rod,length from 1220mm,1525mm,1830mm,3660mm to 6095mm ...