Fit for engine repair and other automotive applications, for steel, cast iron and aluminum, for restoring damaged or worn out threads. Made of high speed steel material, high wear resistance, good toughness, sturdy and durable in use,has a long service life. First, drill out damaged thread using correctly sized drill bit(supplied).Tap re-drilled hole using tap supplied. Then, load coiled insert into applicator. Screw coil into casting, Last,using lug breaking tool, break off tag on inser It is a practical and handy tool, perfect for automotive mechanics, handyman jobs, and DIY home improvement projects. 15pcs thread repair kit including, 10x Wire Thread Inserts, 1x Installation Tool, 1x Break Pin Tool, 1x Twist Drill, 1x Hex Key, 1x Tap, 1x English Instruction, allow you have smooth repairing experience.