About Helicoil Screw Thread Inserts: Helicoil screw thread inserts are precision formed screw thread coils worked into a diamond shape. This wire is then wound into a spiral coil which when installed into Helicoil tapped holes, provides a permanent conventional 60 deg internal screw threads. Helicoil screw thread inserts provide a positive means for protecting and strengthening tapped threads in any material. Helicoil wire thread inserts have an extensive background of tension, torque, shear, vibration and fatigue tests conducted by American industrys leading companies as well as the U.S. Military. Successful applications in the fields of aviation, electronics, industrial, automotive and military equipment provide a wealth of experience and confidence in the performance and reliability of Helicoil wire thread inserts.