Product Description OEMTOOLS 25648 Fix-A-Thread Spark Plug Saver Inserts are designed for rethreading in all materials such as alloys, steel, plastics, magnesium, and more. Specified for automotive, military, aviation and other similar usage, these inserts are made from 18-8 stainless steel wire with a diamond shaped cross section wound to the shape of a spring thread. This positive mechanical locking feature keeps threading in place so there is no loss of compression over time, like you may see with less sophisticated inserts. The corrosion-resistance steel alloy construction extends thread life, even after repeated disassembly and reassembly. Similarly, the high tensile strength wire construction eliminates thread failure due to stripping, vibration, and fatigue. Extreme heat resistance maximizes tapped thread strength under any conditions. Please note that installation requires use of a thread insert tool. These 6 14 - 1.25 inserts are designed for use with a complete thread restorer kit containing a quality intermediate tap, thread repair tool, and easy to follow instructions. When you need more spark plug savers for your thread chaser set, the OEMTOOLS 25648 Fix-A-Thread Spark Plug Saver Inserts are here to save the day. From the Manufacturer OEMTOOLS Fix-A-Thred Inserts are designed to repair stripped threads on "Non-Tapered Seat" spark plugs and for rethreading in all materials such as alloys, steel, plastics and magnesium. They are specified for military, aviation and other similar usage. Inserts are made from high quality 18-8 stainless steel wire with a diamond shaped cross section wound to the shape of a spring thread. Each kit contains a quality intermediate tap, quantity of inserts and easy-to-follow instructions. Functionality Designed to help you repair damaged cylinder heads with blown spark plugs; For both taper seat and gasket type spark plug assemblies Versatility Features 3 insert lengths; Engineered to fit the most common spark plug reaches; Essential parts of any thread restorer kit Resilience High quality 188 stainless steel wire; Specially designed diamond shaped cross section spring thread for extra hold Companion Piece Requires spark plug tool for installation; For use with OEMTOOLS 25647 Spark Plug Thread Repair Kit Metric 14 1.25 Specifications Limited components of a complete 14 1.25 spark plug thread chaser kit; Includes 6 M14 1.25 Inserts; Drill Size 14.25 millimeter and 916 inch