ThreadKits Co. Perma-Coil¬¨¬Æ Maintenance. Repair. Overhaul. KATO Perma-Coil Kits‚àö¬¢ universally accepted method of repairing stripped threads in all types of materials. By using KATO Perma-Coil Kits, damaged threads can be brought back to the original thread size, and better than new. Thread wear, corrosion and galling will be virtually eliminated, and the assembly will be stronger than the original with CoilThread inserts. KATO Perma-Coil Kits consist of: Free-Running Tanged inserts in 1.5 Diameter Nominal Length. High Speed Steel CoilThread Tap. All Steel Threaded Installation mandrel.