Armstrong 70-970 5 Piece Screw Extractor Set The Style Preferred By Professionals Since Straight, Tapering Flutes Grip More Securely Than Spiral Styles Will Not Cause the Screw or Pipe Being Removed to Expand and Bind Can Be Used for Either Right or Left Handed Screws, Bolts, Studs, or Pipe Threads Drill A Hole in the Broken Screw, Bolt or Stud; Lightly Tap the Extractor with A Hammer; and Turn it with A Wrench.