... Drill Rod 4.Tapered Drill Rod Core Drill RodDrill Rod & Coupling (AQ,BQ,NQ,HQ,PQ Drill RodEW,AW,BW,NW,HW Drill Rod )Geotool drill ... are manufactured with a parallel wall.Old Series drill rods E,A,B,N, are available on request. Left hand threaded rods are ... available to special order. Core Drill Rod ...