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 inserts provide a positive means for protecting and strengthening tapped threads in any material. It is used for manufacturing high strength, wear-resistant, high duty, vibration-proof in metallic and non-metallic materials such as Al, Mg alloy, plastic to form M and MJ thread. Now the insert technology has been widely used in many industries such as aerospace, aviation, electricity, instrument, chemical fiber and so on.