Item Type: Spark Plug Thread Repair Tools Thread Insert Size: M14 x 1.25 (thread diameter x pitch) Thread Insert Length: Approx. 17.5mm / 0.7in Thread Insert Material: Stainless Steel Thread Insert Process: Galvanized Tap Size: M16 x 1.25 (thread diameter x pitch) Tap Material: High Speed Steel Package List 1 x M16x1.25 Thread Tap 10 x M14x1.25 Thread Inserts 1INSERTS AND TAP: Including 10pcs M14 x 1.25 thread inserts and a M16 x 1.25 thread tap, is professional spark plug thread repair tool kit. 2STAINLESS STEEL INSERT: These thread inserts are made of stainless steel, with galvanized technology, wear and corrosion resistant. 3HIGH SPEED STEEL TAP: The thread tap is made of high speed steel material, which has high hardness and heat resistance. 4STANDARD THREAD: These inserts and tap have standard thread, the general size is suitable for repairing 14mmx1.25mm spark plug. 5APPLICABLE MACHINE: Tapping is efficient and labor saving, very suitable for gasoline engines, generators, diesel engines, etc.